| 1. |
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| 2. |
- Dreyer, Joshua, et al.
(författare)
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Constraining the Positive Ion Composition in Saturn's Lower Ionosphere with the Effective Recombination Coefficient
- 2021
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Ingår i: The Planetary Science Journal. - : American Astronomical Society. - 2632-3338. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- The present study combines Radio and Plasma Wave Science/Langmuir Probe and Ion and Neutral Mass Spectrometer data from Cassini's last four orbits into Saturn's lower ionosphere to constrain the effective recombination coefficient α300 from measured number densities and electron temperatures at a reference electron temperature of 300 K. Previous studies have shown an influx of ring material causes a state of electron depletion due to grain charging, which will subsequently affect the ionospheric chemistry. The requirement to take grain charging into account limits the derivation of α300 to upper limits. Assuming photochemical equilibrium and using an established method to calculate the electron production rate, we derive upper limits for α300 of ≲ 3 × 10−7 cm3 s−1 for altitudes below 2000 km. This suggests that Saturn's ionospheric positive ions are dominated by species with low recombination rate coefficients like HCO+. An ionosphere dominated by water group ions or complex hydrocarbons, as previously suggested, is incompatible with this result, as these species have recombination rate coefficients > 5 × 10−7 cm3 s−1 at an electron temperature of 300 K.
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| 3. |
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| 4. |
- Dreyer, Joshua, et al.
(författare)
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Identifying Shadowing Signatures of C Ring Ringlets and Plateaus in Cassini Data from Saturn's Ionosphere
- 2022
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Ingår i: The Planetary Science Journal. - : Institute of Physics (IOP). - 2632-3338. ; 3:7
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Tidskriftsartikel (refereegranskat)abstract
- For orbits 288 and 292 of Cassini's Grand Finale, clear dips (sharp and narrow decreases) are visible in the H-2(+) densities measured by the Ion and Neutral Mass Spectrometer (INMS). In 2017, the southern hemisphere of Saturn was shadowed by its rings and the substructures within. Tracing a path of the solar photons through the ring plane to Cassini's position, we can identify regions in the ionosphere that were shadowed by the individual ringlets and plateaus (with increased optical depths) of Saturn's C ring. The calculated shadowed altitudes along Cassini's trajectory line up well with the dips in the H-2(+) data when adjusting the latter based on a detected evolving shift in the INMS timestamps since 2013, illustrating the potential for verification of instrument timings. We can further estimate the mean optical depths of the ringlets/plateaus by comparing the dips to inbound H-2(+) densities. Our results agree well with values derived from stellar occultation measurements. No clear dips are visible for orbits 283 and 287, whose periapsides were at higher altitudes. This can be attributed to the much longer chemical lifetime of H2+ at these higher altitudes, which in turn can be further used to estimate a lower limit for the flow speed along Cassini's trajectory. The resulting estimate of similar to 0.3 km s(-1) at an altitude of similar to 3400 km is in line with prior suggestions. Finally, the ringlet and plateau shadows are not associated with obvious dips in the electron density, which is expected due to their comparatively long chemical (recombination) lifetime.
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| 5. |
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| 6. |
- Kilpeläinen, Tuomas O, et al.
(författare)
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Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P<10(-6) in 19,979 additional individuals. We identify five loci robustly associated (P<5 × 10(-8)) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health.
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| 7. |
- Schmidt, Amand F., et al.
(författare)
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PCSK9 genetic variants and risk of type 2 diabetes : a mendelian randomisation study
- 2017
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Ingår i: The Lancet Diabetes and Endocrinology. - : ELSEVIER SCIENCE INC. - 2213-8587 .- 2213-8595. ; 5:2, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- Background Statin treatment and variants in the gene encoding HMG-CoA reductase are associated with reductions in both the concentration of LDL cholesterol and the risk of coronary heart disease, but also with modest hyperglycaemia, increased bodyweight, and modestly increased risk of type 2 diabetes, which in no way off sets their substantial benefi ts. We sought to investigate the associations of LDL cholesterol-lowering PCSK9 variants with type 2 diabetes and related biomarkers to gauge the likely eff ects of PCSK9 inhibitors on diabetes risk. Methods In this mendelian randomisation study, we used data from cohort studies, randomised controlled trials, case control studies, and genetic consortia to estimate associations of PCSK9 genetic variants with LDL cholesterol, fasting blood glucose, HbA 1c, fasting insulin, bodyweight, waist-to-hip ratio, BMI, and risk of type 2 diabetes, using a standardised analysis plan, meta-analyses, and weighted gene-centric scores. Findings Data were available for more than 550 000 individuals and 51 623 cases of type 2 diabetes. Combined analyses of four independent PCSK9 variants (rs11583680, rs11591147, rs2479409, and rs11206510) scaled to 1 mmol/L lower LDL cholesterol showed associations with increased fasting glucose (0.09 mmol/L, 95% CI 0.02 to 0.15), bodyweight (1.03 kg, 0.24 to 1.82), waist-to-hip ratio (0.006, 0.003 to 0.010), and an odds ratio for type diabetes of 1.29 (1.11 to 1.50). Based on the collected data, we did not identify associations with HbA 1c (0.03%, -0.01 to 0.08), fasting insulin (0.00%, -0.06 to 0.07), and BMI (0.11 kg/m(2), -0.09 to 0.30). Interpretation PCSK9 variants associated with lower LDL cholesterol were also associated with circulating higher fasting glucose concentration, bodyweight, and waist-to-hip ratio, and an increased risk of type 2 diabetes. In trials of PCSK9 inhibitor drugs, investigators should carefully assess these safety outcomes and quantify the risks and benefi ts of PCSK9 inhibitor treatment, as was previously done for statins.
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| 8. |
- Schmidt, Amand F., et al.
(författare)
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Phenome-wide association analysis of LDL-cholesterol lowering genetic variants in PCSK9
- 2019
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Ingår i: BMC Cardiovascular Disorders. - : BMC. - 1471-2261 .- 1471-2261. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: We characterised the phenotypic consequence of genetic variation at the PCSK9 locus and compared findings with recent trials of pharmacological inhibitors of PCSK9. Methods: Published and individual participant level data (300,000+ participants) were combined to construct a weighted PCSK9 gene-centric score (GS). Seventeen randomized placebo controlled PCSK9 inhibitor trials were included, providing data on 79,578 participants. Results were scaled to a one mmol/L lower LDL-C concentration. Results: The PCSK9 GS (comprising 4 SNPs) associations with plasma lipid and apolipoprotein levels were consistent in direction with treatment effects. The GS odds ratio (OR) for myocardial infarction (MI) was 0.53 (95% CI 0.42; 0.68), compared to a PCSK9 inhibitor effect of 0.90 (95% CI 0.86; 0.93). For ischemic stroke ORs were 0.84 (95% CI 0.57; 1.22) for the GS, compared to 0.85 (95% CI 0.78; 0.93) in the drug trials. ORs with type 2 diabetes mellitus (T2DM) were 1.29 (95% CI 1.11; 1.50) for the GS, as compared to 1.00 (95% CI 0.96; 1.04) for incident T2DM in PCSK9 inhibitor trials. No genetic associations were observed for cancer, heart failure, atrial fibrillation, chronic obstructive pulmonary disease, or Alzheimer's disease - outcomes for which large-scale trial data were unavailable. Conclusions: Genetic variation at the PCSK9 locus recapitulates the effects of therapeutic inhibition of PCSK9 on major blood lipid fractions and MI. While indicating an increased risk of T2DM, no other possible safety concerns were shown; although precision was moderate.
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| 9. |
- Shebanits, Oleg, et al.
(författare)
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Photoionization modeling of Titan’s dayside ionosphere
- 2017
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 850:2
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Tidskriftsartikel (refereegranskat)abstract
- Previous modeling studies of Titan’s dayside ionosphere predicts electron numberdensities roughly a factor of 2 higher than observed by the RPWS/Langmuir probe. The issuecan equivalently be described as that the ratio between the calculated electron productionrates and the square of the observed electron number densities result in roughly a factor of4 higher effective recombination coefficient than expected from the ion composition and theelectron temperature. Here we make an extended reassessment of Titan’s dayside ionizationbalance focusing on 34 flybys between TA and T120. Using a re-calibrated dataset and bytaking the presence of negative ions into account we arrive at lower effective recombinationcoefficients compared with earlier studies. The values are still higher than expected from theion composition and the electron temperature, but by a factor of ~2 − 3 instead of a factorof ~4. We have also investigated whether the derived effective recombination coefficientsdisplay dependencies on parameters such as the solar zenith angle, the integrated solar EUVintensity (< 80 nm) and the corotational plasma ram direction and found statisticallysignificant trends which may be explained by a declining photoionization against thebackground ionization by magnetospheric particles (SZA, RAM) and altered photochemistry(EUV). We find that a series of flybys that occurred during solar minimum (2008) and withsimilar flyby geometries are associated with enhanced values of the effective recombinationcoefficient compared with the remaining dataset, which also suggests a chemistry dependenton the sunlight conditions.
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| 10. |
- Shebanits, Oleg, et al.
(författare)
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Titan’s ionosphere : A survey of solar EUV influences
- 2017
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Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 122:7, s. 7491-7503
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Tidskriftsartikel (refereegranskat)abstract
- Effects of solar EUV on positive ions and heavy negative charge carriers (molecular ions, aerosol, and/or dust) in Titan’s ionosphere are studied over the course of almost 12 years, including 78 flybys below 1400 km altitude between TA (October 2004) and T120 (June 2016). The Radio and Plasma Wave Science/Langmuir Probe-measured ion charge densities (normalized by the solar zenith angle) show statistically significant variations with respect to the solar EUV flux. Dayside charge densities increase by a factor of ≈2 from solar minimum to maximum, while nightside charge densities are found to anticorrelate with the EUV flux and decrease by a factor of ≈3–4. The overall EUV dependence of the ion charge densities suggest inapplicability of the idealized Chapman theory below 1200 km in Titan’s ionosphere. Nightside charge densities are also found to vary along Titan’s orbit, with higher values in the sunward magnetosphere of Saturn compared to the magnetotail.
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| 11. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 12. |
- Adamo, Angela, et al.
(författare)
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Legacy ExtraGalactic UV Survey with The Hubble Space Telescope : Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628
- 2017
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Ingår i: Astrophysical Journal. - : IOP PUBLISHING LTD. - 0004-637X .- 1538-4357. ; 841:2
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Tidskriftsartikel (refereegranskat)abstract
- We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes similar to-2 and a truncation of a few times 10(5) M-circle dot. After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find massindependent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (<= 10(4) M-circle dot) clusters, suggesting that a massdependent component is necessary to fully describe the YSC disruption process in NGC 628.
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| 13. |
- Alwall Svennefelt, Catharina, et al.
(författare)
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Evaluating The Swedish Approach to Motivating Improved Work Safety Conditions on Farms: Insights from Fear Appeals and the Extended Parallel Processing Model
- 2018
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Ingår i: Journal of Agromedicine. - 1059-924X .- 1545-0813. ; 23, s. 355-373
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Tidskriftsartikel (refereegranskat)abstract
- Farm work safety intervention programs based on educating and informing have been criticized for not demonstrably improving work safety. We argue that these criticisms are misplaced and that the problem with educating and informing lies not necessarily in the tool, but rather in its implementation. We arrive at this conclusion by systematically investigating eight of the largest farm work safety interventions in Sweden. In particular, we describe how they use fear and other emotional appeals in their communications in an attempt to motivate improved work safety. We then analyze their implementation using the extended parallel processing model (EPPM). We show that, although threat of injury and death is used in the majority of these interventions to motivate individuals, the threat is inconsistent with the behaviors targeted. Other shortcomings and implications for implementing wide-scale farm work safety interventions are discussed.
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| 14. |
- Alwall Svennefelt, Catharina, et al.
(författare)
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Work safety interventions and threat complexity - A formative investigation into why farmers do not act safely
- 2019
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Ingår i: Annals of Agricultural and Environmental Medicine. - : Institute of Rural Health. - 1232-1966 .- 1898-2263. ; 26, s. 280-289
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Tidskriftsartikel (refereegranskat)abstract
- Introduction. Fear appeals are a common tactic used in work safety interventions to motivate farmers to adopt safer behaviours. They begin by introducing a threat, followed by information on how to remove the threat. However, fear appeals tend to be ineffective when developed without a firm grasp of the cognitive processes underlying behavioural change. Although previous research on farm safety interventions have investigated fear appeals, they have focused on very narrow threats and behaviours, such as tractor or cow safety, while others have studied the threats but not the cognitive processing. Consequently, not enough is known about the range of threats that evoke fear, how farmers behave when under threat, or their general cognitive beliefs regarding self-efficacy, response cost and response efficacy. In In this study, 23 Swedish Farmers were interviewed and participated in a work safety intervention to identify the range of threats farmers perceive, and actions taken to remove those threats.Materials and method. The extended parallel processing model was used to gain insights into how farmers cognitively processed threats and their subsequent behaviour. Interestingly, it was found that farmers were more fearful of work safety threats related to family members and employees-yet the actions they took to reduce threats were mostly personal in nature. To help explain this finding, a typology of threat complexity was developed by the authors.Results. It was found that simple, common, and direct threats to safety tended to lead to adaptive, threat-reducing behaviours, whereas complex, general, or indirect threats promoted more maladaptive behaviours that reduced fear, but not the threats.
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| 15. |
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| 16. |
- Aquila, Andrew, et al.
(författare)
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Time-resolved protein nanocrystallography using an X-ray free-electron laser
- 2012
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Ingår i: Optics Express. - 1094-4087. ; 20:3, s. 2706-2716
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the use of an X-ray free electron laser synchronized with an optical pump laser to obtain X-ray diffraction snapshots from the photoactivated states of large membrane protein complexes in the form of nanocrystals flowing in a liquid jet. Light-induced changes of Photosystem I-Ferredoxin co-crystals were observed at time delays of 5 to 10 µs after excitation. The result correlates with the microsecond kinetics of electron transfer from Photosystem I to ferredoxin. The undocking process that follows the electron transfer leads to large rearrangements in the crystals that will terminally lead to the disintegration of the crystals. We describe the experimental setup and obtain the first time-resolved femtosecond serial X-ray crystallography results from an irreversible photo-chemical reaction at the Linac Coherent Light Source. This technique opens the door to time-resolved structural studies of reaction dynamics in biological systems.
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| 17. |
- Arnlund, David, et al.
(författare)
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Visualizing a protein quake with time-resolved X-ray scattering at a free-electron laser
- 2014
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Ingår i: Nature Methods. - : Springer Science and Business Media LLC. - 1548-7091 .- 1548-7105. ; 11:9, s. 923-926
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Tidskriftsartikel (refereegranskat)abstract
- We describe a method to measure ultrafast protein structural changes using time-resolved wide-angle X-ray scattering at an X-ray free-electron laser. We demonstrated this approach using multiphoton excitation of the Blastochloris viridis photosynthetic reaction center, observing an ultrafast global conformational change that arises within picoseconds and precedes the propagation of heat through the protein. This provides direct structural evidence for a 'protein quake': the hypothesis that proteins rapidly dissipate energy through quake-like structural motions.
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| 18. |
- Barty, A., et al.
(författare)
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Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements
- 2012
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Ingår i: Nature Photonics. - 1749-4885 .- 1749-4893. ; 6:1, s. 35-40
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Tidskriftsartikel (refereegranskat)abstract
- X-ray free-electron lasers have enabled new approaches to the structural determination of protein crystals that are too small or radiation-sensitive for conventional analysis1. For sufficiently short pulses, diffraction is collected before significant changes occur to the sample, and it has been predicted that pulses as short as 10 fs may be required to acquire atomic-resolution structural information1, 2, 3, 4. Here, we describe a mechanism unique to ultrafast, ultra-intense X-ray experiments that allows structural information to be collected from crystalline samples using high radiation doses without the requirement for the pulse to terminate before the onset of sample damage. Instead, the diffracted X-rays are gated by a rapid loss of crystalline periodicity, producing apparent pulse lengths significantly shorter than the duration of the incident pulse. The shortest apparent pulse lengths occur at the highest resolution, and our measurements indicate that current X-ray free-electron laser technology5 should enable structural determination from submicrometre protein crystals with atomic resolution.
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| 19. |
- Barucca, G., et al.
(författare)
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The potential of Λ and Ξ- studies with PANDA at FAIR
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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Tidskriftsartikel (refereegranskat)abstract
- The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
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| 20. |
- Berndt, Sonja I., et al.
(författare)
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Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:5, s. 501-U69
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Tidskriftsartikel (refereegranskat)abstract
- Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.
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| 21. |
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| 22. |
- Bivalacqua, Trinity J., et al.
(författare)
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Dysregulation of cGMP-dependent protein kinase 1 (PKG-1) impairs erectile function in diabetic rats: influence of in vivo gene therapy of PKG1 alpha
- 2007
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Ingår i: BJU International. - 1464-4096 .- 1464-410X. ; 99:6, s. 1488-1494
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the expression of cGMP-dependent protein kinase 1 (PKG1)alpha and PKG1 beta in the corpus cavernosum, and to evaluate the effect of adenoviral gene transfer of PKG1 alpha to the erectile compartment on erectile function in a rat model of diabetes. Diabetic (DM; induced by streptozotocin) male Sprague Dawley rats were transfected with adenoviruses (AdCMV beta gal or AdCMVPKG1 alpha, in 10 rats each) 2 months after the induction of DM. Intracavernosal pressure (ICP) during stimulation of the cavernosal nerve (CN) was assessed, and compared with mean arterial pressure (MAP). Erectile tissue was harvested for Western blot analysis, immunohistochemistry and total PKG activity. Ten age-matched rats without DM served as the control. Compared to controls, AdCMV beta gal-transfected DM rats had significantly lower peak ICP responses, ICP/MAP ratios, and filling rates during CN stimulation. In DM rats transfected with AdCMVPKG1 alpha, peak ICP, ICP/MAP ratios and filling rates were significantly better than in DM rats transfected with the reporter gene. As assessed by Western blot and immunohistochemistry, expression of PKG1 alpha and PKG1 beta was lower in corporal tissue from DM AdCMV beta gal-transfected rats than in controls. PKG1 alpha expression was improved after AdCMVPKG1 alpha gene therapy. Total PKG activity was lower in DM rat corporal tissue than in controls, and PKG1 alpha gene transfer significantly improved DM corporal PKG activity to a value greater than in the control. PKG1 alpha and PKG1 beta activities are reduced in the erectile tissue of the diabetic rat, and gene transfer of PKG1 alpha to the penis restored PKG activity and erectile function in vivo in diabetic rats. Gene therapy procedures targeting PKG1 alpha might be an interesting future therapeutic approach to overcome diabetic erectile dysfunction resistant to oral pharmacotherapy.
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| 23. |
- Bombarda, F., et al.
(författare)
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Runaway electron beam control
- 2019
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Tidskriftsartikel (refereegranskat)
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Davidsson, Per, 1957-, et al.
(författare)
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Institutional forces : The invisible hand that shapes venture ideas?
- 2006
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Ingår i: International Small Business Journal. - : SAGE Publications. - 0266-2426 .- 1741-2870. ; 24:2, s. 115-131
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Tidskriftsartikel (refereegranskat)abstract
- Institutional theory is employed for examining how and to what extent external pressure leads to changes in the venture idea during the start-up and early life of new, knowledge-intensive ventures. From a population of 321 young, knowledge-intensive firms that underwent a training program at Linkping University, Sweden, structured telephone interview data were obtained from 167 firms. The results confirmed that the venture idea had undergone more change in ventures that had more external owners, a dominant customer, and an incubator location. The results imply that institutional theory is a meaningful tool for understanding why and how venture ideas change over time.
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| 29. |
- Davidsson, Per, et al.
(författare)
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The discovery process : External influences on refinement of the venture idea
- 2004
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Ingår i: Frontiers of Entrepreneurship Research 2004. - Wellesley, MA. : Babson College. - 0910897255 ; , s. 327-337
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we use institutional theory for examining how and to what extent external pressure leads to changes in the venture idea during the start-up and early life of new, knowledge-intensive ventures. From a population of 321 young, knowledge-intensive firms that underwent a training program at Linköping University, we have telephone interview data on 167. The results confirmed that the venture idea had undergone more change in ventures that had more external owners, a dominant customer, and an incubator location. Our results imply that institutional theory is a meaningful tool for understanding why and how venture ideas change over time.
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Dods, Robert, 1989, et al.
(författare)
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From Macrocrystals to Microcrystals: A Strategy for Membrane Protein Serial Crystallography.
- 2017
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Ingår i: Structure. - : Elsevier BV. - 1878-4186 .- 0969-2126. ; 25:9, s. 1461-1468
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Tidskriftsartikel (refereegranskat)abstract
- Serial protein crystallography was developed at X-ray free-electron lasers (XFELs) and is now also being applied at storage ring facilities. Robust strategies for the growth and optimization of microcrystals are needed to advance the field. Here we illustrate a generic strategy for recovering high-density homogeneous samples of microcrystals starting from conditions known to yield large (macro) crystals of the photosynthetic reaction center of Blastochloris viridis (RCvir). We first crushed these crystals prior to multiple rounds of microseeding. Each cycle of microseeding facilitated improvements in the RCvir serial femtosecond crystallography (SFX) structure from 3.3-Å to 2.4-Å resolution. This approach may allow known crystallization conditions for other proteins to be adapted to exploit novel scientific opportunities created by serial crystallography.
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| 34. |
- Dods, Robert, 1989, et al.
(författare)
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Ultrafast structural changes within a photosynthetic reaction centre.
- 2021
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 589:7841, s. 310-314
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Tidskriftsartikel (refereegranskat)abstract
- Photosynthetic reaction centres harvest the energy content of sunlight by transporting electrons across an energy-transducing biological membrane. Here we use time-resolved serial femtosecond crystallography1 using an X-ray free-electron laser2 to observe light-induced structural changes in the photosynthetic reaction centre of Blastochloris viridis on a timescale of picoseconds. Structural perturbations first occur at the special pair of chlorophyll molecules of the photosynthetic reaction centre that are photo-oxidized by light. Electron transfer to the menaquinone acceptor on the opposite side of the membrane induces a movement of this cofactor together with lower amplitude protein rearrangements. These observations reveal how proteins use conformational dynamics to stabilize the charge-separation steps of electron-transfer reactions.
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| 35. |
- Dreyer, Joshua, et al.
(författare)
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Utilizing Helium Ion Chemistry to Derive Mixing Ratios of Heavier Neutral Species in Saturn's Equatorial Ionosphere
- 2023
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 128:6
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Tidskriftsartikel (refereegranskat)abstract
- A surprisingly strong influx of organic-rich material into Saturn's upper atmosphere from its rings was observed during the proximal obits of the Grand Finale of the Cassini mission. Measurements by the Ion and Neutral Mass Spectrometer (INMS) gave insights into the composition of the material, but it remains to be resolved what fraction of the inferred heavy volatiles should be attributed as originating from the fragmentation of dust particles in the instrument versus natural ablation of grains in the atmosphere. In the present study, we utilize measured light ion and neutral densities to further constrain the abundances of heavy volatiles in Saturn's ionosphere through a steady-state model focusing on helium ion chemistry. We first show that the principal loss mechanism of He+ in Saturn's equatorial ionosphere is through reactions with species other than H-2. Based on the assumption of photochemical equilibrium at altitudes below 2,500 km, we then proceed by estimating the mixing ratio of heavier volatiles down to the closest approaches for Cassini's proximal orbits 288 and 292. Our derived mixing ratios for the inbound part of both orbits fall below those reported from direct measurements by the INMS, with values of similar to 2 x 10(-4) at closest approaches and order-of-magnitude variations in either direction over the orbits. This aligns with previous suggestions that a large fraction of the neutrals measured by the INMS stems from the fragmentation of infalling dust particles that do not significantly ablate in the considered part of Saturn's atmosphere and are thus unavailable for reactions. Plain Language Summary During the final orbits of the Cassini mission, the spacecraft flew between Saturn's rings and the planets upper atmosphere. The onboard plasma instruments detected a large amount of ring particles falling toward the planet, but direct measurements of the composition of these grains are complicated due to the high spacecraft speed and instrumental effects. In this study, we present an independent method to estimate the abundance of heavier neutral species entering the atmosphere from infalling ring material. This method relies on helium ion chemistry and the measured light ion and neutral densities. Our results generally fall below those inferred from direct measurements. Together with comparisons to other studies, this potentially suggests that a large fraction of the infalling neutral species do not significantly ablate in the considered part of Saturn's atmosphere (and remain bound to the dust grains instead) and are thus unavailable for reactions.
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| 36. |
- Ekelund Axelson, Lena, et al.
(författare)
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Communicating GHG mitigating food consumption in-store An observational study of food retailers in five European countries
- 2014
-
Ingår i: British Food Journal. - 0007-070X .- 1758-4108. ; 116, s. 1618-1635
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Tidskriftsartikel (refereegranskat)abstract
- Purpose - Current food consumption patterns contribute negatively to greenhouse gas (GHG) emissions and climate change. Positioned at the interface between producers and consumers, retailers have the potential to reduce this problem through informing their customers on the consequences of their actions. The purpose of this paper is to understand the variety of ways European retailers go about informing their customers on the linkage between food choice and climate change as well as which actions they advocate in-store to reduce the problem.Design/methodology/approach - In-store walkthroughs lasting between 40 minutes and 1.5 hours were carried out at 30 grocery stores in five European countries to identify climate mitigating communications. The observations targeted any message produced and transmitted by the retailer where links between food and climate change were drawn.Findings - The diversity in climate mitigating food communication we expected to find across Europe did not materialize. Only four out of the 30 retailers visited transmitted to their customers any information showing a direct link between food consumption and climate change. Indirectly, the authors found some retailers communicating food choices believed to lead to GHG reduction without linking them to climate change. Finally the authors found several retailers communicating what the authors argue are ambiguous messages to their customers where sustainability issues were confounded with climate ones. The dearth of climate mitigating food communications reveals the complexity in informing customers on such issues but also a possible lack of interest on the part of both parties.Originality/value - This research contributes empirically to knowledge of how retailers communicate climate mitigating food consumption to consumers.
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| 37. |
- Ekelund Axelson, Lena, et al.
(författare)
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Klimatmärkt livsmedelsbutik : så kan handeln bidra till minskad klimatpåverkan genom att underlätta konsumentens val
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Klimathotet påkallar stora förändringar i konsumtionsmönster och kostvanor. Projektet Klimatmärkt livsmedelsbutik har haft som syfte att utreda hur handeln kan bidra till minskad klimatpåverkan genom att underlätta konsumentens val. Förutom klimatpåverkan orsakar livsmedelsproduktionen också annan miljöpåverkan, såsom övergödning, spridning av bekämpningsmedel och förlust av biologisk mångfald. Att bara fokusera på klimatet riskerar förbättring på ett ställe och försämring på ett annat. Därför beslutades tidigt att projektet även måste belysa dessa potentiella målkonflikter. Två delområden har ingått; miljökonsekvensanalyser samt konsumentbeteende och marknadskommunikation, vilket har krävt en tvärvetenskaplig ansats och olika forskningsmetoder. Projektet tog sin början i miljökonsekvensanalyser av olika livsmedels miljöpåverkan med hjälp av livscykelanalys, vars resultat sedan utgjorde informationsunderlag, bl.a en Köttguide, för kommunikationen till konsument. Inom konsumentbeteende och marknadskommunikation har såväl kvalitativ som kvantitativ metod använts. För att få en bild över vad som kommuniceras i butik genomfördes intervjuer med butiksansvariga och en observationsstudie i 30 större europeiska butiker. Enkätundersökningar gjordes med 184 resp. 470 konsumenter. Köttguiden testades i fokusgruppintervjuer. Kvantitativa studier gjordes med 222 slumpvis utvalda personer för att utreda hur intentionen att ändra sin köttkonsumtion kan förutsägas och med drygt 600 konsumenter i ett butiksexperiment för att studera effekten av naturljud på konsumenters betalningsvilja för klimatvänliga respektive ekologiska grönsaker. Resultat från konsumentstudierna visade på viss förvirring kring märkning och på behovet av ett enklare signalsystem. De vanligaste svaren kring vilka klimatåtgärder som är viktigast var att köpa närproducerad mat, köpa frukt och grönt efter säsong och undvika att slänga mat, medan den viktiga frågan om köttet hamnade längre ner på listan. Livscykelanalyser, kompletterade med litteraturstudier, visar att säsongsmässig konsumtion av grönsaker visserligen kan minska utsläppen, men att den minskningen är liten i förhållande till den av minskad köttkonsumtionen. Den viktigaste åtgärden för att reducera matens klimatpåverkan är att minska konsumtionen av animaliska produkter och helst ersätta dessa med vegetabiliska alternativ. Butiksobservationerna och intervjuer med butiksansvariga visade att det i stort sett saknades vägledning i butikerna. Studierna underströk behovet av Köttguiden, en vägledning som rangordnar olika proteinkällor (även vegetabiliska) i förhållande till klimat, biologisk mångfald, kemiska bekämpningsmedel samt djurskydd och bete, med hjälp av ett tydligt signalsystem (trafikljus). Matinköp och val av livsmedel styrs i stor utsträckning av preferenser och vanor, som kan vara svåra att förändra. För att övertyga konsumenter om att förändra sitt beteende måste man kommunicera budskap som bidrar till ökad motivation till förändring.. Med hjälp av Protection Motivation- teorin undersöktes vilka faktorer som förutsäger individers avsikter att ändra sitt beteende, efter att de blivit fakta kring klimathotet och matens klimatpåverkan har presenterats för dem. Studien visade att budskap i syfte att uppmuntra en mindre klimatbelastande livsmedelskonsumtion, måste vara sådana att konsumenterna känner att en sådan förändring är möjlig och att den får effekt. Resultaten tyder också på att människor bryr sig mer om klimatförändringarnas risker för andra - för personer i andra länder eller för djurlivet – än för dem själva eller deras närstående. En slutsats blir då att altruistiska snarare än egoistiska argument bör lyftas fram i marknadsföringen. I ett butiksexperiment användes skyltning och naturljud – fågelsång-, för att testa om detta gav en koppling till naturen och därmed ökade viljan att köpa produkter, i detta fall morötter, märkta ”klimatvänliga”. Fågelsången hade ingen inverkan på konsumenternas koppling till naturen. Men bland de konsumenter som uttryckte en hög samhörighet med naturen, fanns det en högre betalningsvilja för klimatmärkta produkter än för produkter utan märkning, jämfört med de konsumenter som uttryckte en låg samhörighet med naturen. När konsumenterna, i ett butiksexperiment med mjölk, erbjöds information om en varas lägre klimatpåverkan på ett enkelt sätt precis vid köptillfället ökade försäljningen av den varan, men samtidigt minskade försäljningen av andra miljömärkta varor. Klimatbudskapen är komplicerade och konsumenten har oklara uppfattningar om hur maten påverkar klimatet. Budskapen och valen i butik måste vara enkla: Att fokusera på det som konsumenten tror sig klara av och som de tror kan få effekt, är viktigt. Köttguiden har rönt stor uppmärksamhet och testats med positivt resultat som ett hjälpmedel för klimatsmarta matval. Rekommendationerna till handeln kan sammanfattas: Gör det enkelt att välja och laga vegetariskt, använd Köttguiden bland personalen, se över köttsortimentet, öka försäljningen av baljväxter, rotfrukter, frukt och grönsaker och använd ekologiskt, säsong och hälsa som indirekta klimatbudskap.
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| 38. |
- Elks, Cathy E, et al.
(författare)
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Thirty new loci for age at menarche identified by a meta-analysis of genome-wide association studies
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:12, s. 1077-85
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Tidskriftsartikel (refereegranskat)abstract
- To identify loci for age at menarche, we performed a meta-analysis of 32 genome-wide association studies in 87,802 women of European descent, with replication in up to 14,731 women. In addition to the known loci at LIN28B (P = 5.4 × 10⁻⁶⁰) and 9q31.2 (P = 2.2 × 10⁻³³), we identified 30 new menarche loci (all P < 5 × 10⁻⁸) and found suggestive evidence for a further 10 loci (P < 1.9 × 10⁻⁶). The new loci included four previously associated with body mass index (in or near FTO, SEC16B, TRA2B and TMEM18), three in or near other genes implicated in energy homeostasis (BSX, CRTC1 and MCHR2) and three in or near genes implicated in hormonal regulation (INHBA, PCSK2 and RXRG). Ingenuity and gene-set enrichment pathway analyses identified coenzyme A and fatty acid biosynthesis as biological processes related to menarche timing.
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| 39. |
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| 40. |
- Fernqvist, Fredrik, et al.
(författare)
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Who's to Blame for Tasteless Tomatoes? The Effect of Tomato Chilling on Consumers' Taste Perceptions
- 2012
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 77, s. 193-198
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Tidskriftsartikel (refereegranskat)abstract
- The most common stated reason to consumer dissatisfaction with tomatoes is lack of flavour. It has been shown that a common storage practice among consumer households is to store tomatoes in the refrigerator, which have a negative impact on tomato taste. Thus, consumer postharvest treatment in home may be a reason to diminishing taste. In a Swedish consumer survey we find that 53 % are dissatisfied with tomato taste and that 74 % store their tomatoes after purchase in a temperature below recommendations. Research done on the effect of tomato storage has led to the suggestion that growers should educate consumers on handling practices in order to remove the negative effect chilling has on taste experience. However, past research has been conducted on samples that potentially do not represent the target consumer, as trained sensory panels do not perceive taste as untrained consumers do. Based on previous empirical studies using expert panels, we hypothesise that panels consisting of ordinary consumers will prefer tomatoes stored in room temperature to those chilled under ordinary refrigerated conditions (i.e. 7 degrees C) regardless of variety. Thus, we replicate and challenge past findings and normative recommendations through the use of two experiments involving consumer panels evaluating two varieties of tomatoes, 'Arvento' and 'Tiesto', stored two days in refrigerator (7 degrees C) and room temperature (21 degrees C) respectively. We found a significant difference in consumer liking for 'Arvento' that were unchilled (M=6.443, SD=+/- 1.765) and chilled (M=5.849, SD=+/- 1.894), t(351)=4.270, p<0.001 (two tailed), albeit with a small effect size (eta squared statistic (.049)). No significant difference in liking was found for the 'Tiesto' variety. We find, contrary to previous research, that storage temperature has no or only a marginal effect on perceived taste among respondents in untrained consumer panels for the two varieties in our trial. Theoretical and practical implications are discussed.
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| 41. |
- Fitz-Koch, Sarah, et al.
(författare)
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Entrepreneurship in the agricultural sector : A literature review and future research opportunities
- 2018
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Ingår i: Entrepreneurship. - : Sage Publications. - 1042-2587 .- 1540-6520. ; 42:1, s. 129-166
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Forskningsöversikt (refereegranskat)abstract
- Heeding calls for contextualizing entrepreneurship research and for greater attention to the role of sector in entrepreneurship research, we conduct a systematic literature review of extant research in agricultural entrepreneurship. Recent and rapid vertical integration and rationalization within the agricultural sector provides a dynamic setting for scholars to investigate entrepreneurship theory and practice. We identify three key contextual dimensions of the agricultural sector: identity, family, and institutions, which provide promising opportunities for future research and the potential to contribute to and extend current theoretical and empirical analyses of entrepreneurship research.
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| 42. |
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| 43. |
- Ganesh, Santhi K., et al.
(författare)
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Loci influencing blood pressure identified using a cardiovascular gene-centric array
- 2013
-
Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 22:8, s. 1663-1678
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Tidskriftsartikel (refereegranskat)abstract
- Blood pressure (BP) is a heritable determinant of risk for cardiovascular disease (CVD). To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP) and pulse pressure (PP), we genotyped 50 000 single-nucleotide polymorphisms (SNPs) that capture variation in 2100 candidate genes for cardiovascular phenotypes in 61 619 individuals of European ancestry from cohort studies in the USA and Europe. We identified novel associations between rs347591 and SBP (chromosome 3p25.3, in an intron of HRH1) and between rs2169137 and DBP (chromosome1q32.1 in an intron of MDM4) and between rs2014408 and SBP (chromosome 11p15 in an intron of SOX6), previously reported to be associated with MAP. We also confirmed 10 previously known loci associated with SBP, DBP, MAP or PP (ADRB1, ATP2B1, SH2B3/ATXN2, CSK, CYP17A1, FURIN, HFE, LSP1, MTHFR, SOX6) at array-wide significance (P 2.4 10(6)). We then replicated these associations in an independent set of 65 886 individuals of European ancestry. The findings from expression QTL (eQTL) analysis showed associations of SNPs in the MDM4 region with MDM4 expression. We did not find any evidence of association of the two novel SNPs in MDM4 and HRH1 with sequelae of high BP including coronary artery disease (CAD), left ventricular hypertrophy (LVH) or stroke. In summary, we identified two novel loci associated with BP and confirmed multiple previously reported associations. Our findings extend our understanding of genes involved in BP regulation, some of which may eventually provide new targets for therapeutic intervention.
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| 44. |
- Gaulton, Kyle J, et al.
(författare)
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Genetic fine mapping and genomic annotation defines causal mechanisms at type 2 diabetes susceptibility loci.
- 2015
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 47:12, s. 1415-1415
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Tidskriftsartikel (refereegranskat)abstract
- We performed fine mapping of 39 established type 2 diabetes (T2D) loci in 27,206 cases and 57,574 controls of European ancestry. We identified 49 distinct association signals at these loci, including five mapping in or near KCNQ1. 'Credible sets' of the variants most likely to drive each distinct signal mapped predominantly to noncoding sequence, implying that association with T2D is mediated through gene regulation. Credible set variants were enriched for overlap with FOXA2 chromatin immunoprecipitation binding sites in human islet and liver cells, including at MTNR1B, where fine mapping implicated rs10830963 as driving T2D association. We confirmed that the T2D risk allele for this SNP increases FOXA2-bound enhancer activity in islet- and liver-derived cells. We observed allele-specific differences in NEUROD1 binding in islet-derived cells, consistent with evidence that the T2D risk allele increases islet MTNR1B expression. Our study demonstrates how integration of genetic and genomic information can define molecular mechanisms through which variants underlying association signals exert their effects on disease.
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| 45. |
- Heid, Iris M, et al.
(författare)
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Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:11, s. 949-960
-
Tidskriftsartikel (refereegranskat)abstract
- Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻¹³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.
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| 46. |
- Hunter, Erik, et al.
(författare)
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Celebrity capital as a strategic asset : Implications for new venture strategies
- 2009
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Ingår i: Entrepreneurial Strategic Content. - Greenwich, Conn. : JAI Press. - 9781848554221 ; , s. 137-160
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Despite an increase in businesses started by celebrities, we have limited understanding as to how celebrity entrepreneurs benefit new ventures. Drawing on a reputational capital perspective, we develop the notion of celebrity capital and show how it can be used to uniquely differentiate the venture and to overcome liabilities of newness. We discuss how celebrity capital can negatively influence the venture in terms of limiting the scope of the venture and when negative information about the celebrity surfaces. We discuss the different strategic implications of celebrity capital for ventures using celebrity entrepreneurs versus endorsers.
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| 47. |
- Hunter, Erik, et al.
(författare)
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Celebrity entrepreneurship : The effect of negative celebrity information on the new venture
- 2008
-
Ingår i: Babson College Entrepreneurship Research Conference (BCERC) 2008.
-
Konferensbidrag (populärvet., debatt m.m.)abstract
- Increasingly, celebrities engage in business not just as endorsers but also with a financial stake and decision-making role in the business. Whether initiated by the celebrity or by other founders, we refer to such instances of new ventures entering the market with a celebrity engaged in such ways as “celebrity entrepreneurship”. Partnering with a celebrity rather than contracting them as a celebrity endorser is not without its risks. Even the most mundane information concerning the lives of celebrities is newsworthy so when negative information concerning a celebrity surfaces, it spreads fast. When celebrities are involved with starting or owning a company, they carry their name with them. Under such circumstances, negative information about the celebrity might reflect negatively on the company as well. Our findings suggest that negative information a) leads to negative attitudes towards the new venture and promotion, b) which is comparable worse for celebrity entrepreneur led new ventures; c) new ventures can potentially reduce damage to their brand by distancing themselves from the celebrity, d) however, such a maneuver may not be as effective when the new venture is run by a celebrity entrepreneur.
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| 48. |
- Hunter, Erik, et al.
(författare)
-
Celebrity Entrepreneurship : Insights for New Venture Strategy
- 2007
-
Ingår i: Frontiers of entrepreneurship research 2007. - Wellesley, MA. : Babson College. - 091089728X
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this study we investigate a relatively new empirical phenomenon: Celebrity Entrepreneurship. By conducting three experiments on a total of 314 participants, designed to reflect a new venture promotional setting, we find support for our hypothesis that celebrity entrepreneurs are more effective communicators than ordinary celebrity endorsers. This is apparently due to an increase in their perceived involvement with the companies they endorse. Specifically, our results show that increasing levels of perceived involvement has a positive effect on attitudes towards new ventures and advertisements.
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| 49. |
- Hunter, Erik, et al.
(författare)
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Celebrity Entrepreneurship : Communication Effectiveness through Perceived Involvement
- 2007
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Ingår i: International Journal of Entrepreneurship and Small Business. - 1476-1297 .- 1741-8054. ; 4:5, s. 505-527
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Tidskriftsartikel (refereegranskat)abstract
- Increasingly, celebrities appear not only as endorsers for products but are apparently involved in entrepreneurial roles—as initiators, part owners and/or in managerial capacities—in the ventures that market the products they promote. We call this phenomenon Celebrity Entrepreneurship. Whether or not this type of involvement on the part of the celebrity is original and genuine, it may be suspected that celebrity entrepreneurs are more effective communicators than typical celebrity endorsers. This research hypothesizes that such is the case. Further, we hypothesize that this is because celebrity entrepreneurship leads to higher perceptions of a source’s Involvement—an endorser quality hitherto neglected in the marketing communication literature—which in turn affects traditional outcome variables such as Aad (Attitude toward the ad) and Abr (Attitude towards the brand). Based on two experiments using subjects from the relevant product target group (n=88 and n=77) we tested their reactions to advertisements containing the celebrity Cameron Diaz after exposure to one of three experimental conditions: entrepreneur; mere endorser, and no information (control). The results confirm that a) involvement can successfully be operationalized as distinct from variables previously shown to influence communicator effectiveness (trustworthiness, attractiveness and expertise), b) involvement has a positive effect on Aad and Abr over and above the traditional predictors and control variables, and c) the celebrity entrepreneur condition in the experimental manipulation leads to increased perceived involvement.
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| 50. |
- Hunter, Erik, et al.
(författare)
-
Celebrity Entrepreneurship : Insights for New Venture Strategy
- 2008
-
Ingår i: Frontiers of entrepreneurship research 2007. - Wellesley, MA : Babson College. - 091089728X
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this study we investigate a relatively new empirical phenomenon: Celebrity Entrepreneurship. By conducting three experiments on a total of 314 participants, designed to reflect a new venture promotional setting, we find support for our hypothesis that celebrity entrepreneurs are more effective communicators than ordinary celebrity endorsers. This is apparently due to an increase in their perceived involvement with the companies they endorse. Specifically, our results show that increasing levels of perceived involvement has a positive effect on attitudes towards new ventures and advertisements.
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