| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Bastviken, Sofia, et al.
(författare)
-
Läget i länet? Tillståndet i Östergötlands vattenmiljöer
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Östergötland finns många varierande och värdefulla vattenmiljöer. Mer än hälften av länets vattenmiljöer har dock inte tillräckligt bra vattenkvalitet för att nå upp till de mål som antagits inom Sverige och EU. Länets vatten har under lång tid varit utsatt för olika typer av miljöpåverkan från mänskliga verksamheter. I många fall leder det till miljöproblem som algblomningar eller förstörda livsmiljöer.Flera åtgärder genomförs nu för att för att förbättra miljötillståndet i länets vatten. De största hoten mot Östergötlands vattenmiljöer är övergödning, utsläpp av miljögifter och fysisk påverkan i form av t.ex. dikning, dämning och omledning av vatten. Andra mindre omfattande problem är försurning och införsel av främmande arter som ibland tränger undan våra inhemska arter.Övergödning är främst ett problem i sjöar och vattendrag på östgötaslättensamt i kustvattnet. Läckage från jordbruksmark, utsläpp av avloppsvatten och förbränning av fossila bränslen är några av de källor som tillför näringsämnen till vattenmiljön. För mycket näring leder bland annat till algblomningar, grumling och syrefria bottnar.Från syrefria bottnar läcker i sin tur fosfor till ovanliggande vatten och det krävs därför kraftiga åtgärdsinsatser för att vända en negativ spiral. Många åtgärder genomförs för att minska utsläpp av näringsämnen, och utsläpp från industri och reningsverk har minskat markant. Än så länge kan vi dock inte utifrån våra miljödata se några tydliga förbättringar i miljötillståndet. Detta beror på att det efter decennier av utsläpp finns stora mängder näringsämnen upplagrade i mark och bottensediment. De ”gamla synderna” medför att det tar tid innan vi ser resultat av de åtgärder som hittills genomförts.De senaste tio åren har dessutom varit blötare än tidigare och under nederbördsrika år läcker generellt mer näringsämnen från mark till vatten. Länsstyrelsen arbetar tillsammans med kommuner, vattenråd och andra berörda parter inom länet för att förbättra miljötillståndet.Takten på åtgärdsarbetet har ökat under senare år och förhoppningsvis återspeglar det sig snart i våra mätdata. Mycket har också hänt på miljögiftsområdet och halterna av flera miljögifter har minskat under senare år. Men faran är inte över, hela tiden framställs nya kemikalier som förr eller senare hamnar i vattenmiljön. Genom så kallade screeningundersökningar försöker Länsstyrelsen hitta nya ämnen som kan hota miljön och människors hälsa. Nya regelverk inom EU gör det också enklare att få kontroll på kemikalier samt att minska utsläppen. Många av de ämnen och produkter som vi använder i vår vardag återfinns i miljön, till exempel bisfenol A och nonylfenol. Länsstyrelsen och kommunerna arbetar också för att minska spridning av föroreningar från redan förorenade mark- och vattenområden som till exempel i Gusum och Valdemarsviken. Ett kvarstående problem, i såväl Östergötland som övriga Sverige, är också det höga kvicksilverinnehållet i sötvattenslevande fisk. För att öka kunskaperna om förekomst och spridning av miljögifter i länet har Länsstyrelsen och Motala ströms vattenvårdsförbund utökat övervakningen av miljögifter.Ett annat utbrett miljöproblem i länets sjöar och vattendrag är olika former av fysiska förändringar. Människan har under lång tid utnyttjat vattnet för olika ändamål, ofta utan hänsyn till växt- och djurliv. Flera sjöar har torrlagts eller sänkts för att kunna bruka marker som översvämmats eller varit försumpade. Nästan alla större vattendrag i länet är idag utbyggda med vattenkraftverk och regleringsmagasin.Ingreppen har förändrat vattnets naturliga väg och flöde, och dammar utgör dessutom ofta vandringhinder för t.ex. fisk. I länet pågår nu flera projekt för att åtgärda vandringshinder och återställa rensade vattendrag till mer naturliga förhållanden, med bättre förutsättningar för fisk och andra organismer.Ett mindre utbrett problem i länets sjöar och vattendrag är försurning. Tack vare att stora områden i länet består av kalkhaltiga jordar som buffrar surt nedfall har vi inte lika stora problem med försurning som många andra län. Problem med försurning är störst i länets norra och södra skogsbygder. Orsaker till försurningen är utsläpp från transporter, energianläggningar, industri och jordbruk.Utsläppen av svavel och kväve har minskat kraftigt under de senaste tio åren, men återhämtningen tar tid och flera vatten måste därför kalkas under en lång tid framöver.I länets vattenmiljöer finns flera främmande arter som kommit hit med människans hjälp. De allra flesta arter är harmlösa, medan vissa tränger undan våra inhemska arter och därmed minskar den biologiska mångfalden. En art som ställt till med stora problem i länets vatten är signalkräftan. Signalkräftan sprider kräftpest till vår inhemska flodkräfta och flodkräftan är nu akut hotad. Den låga salthalten gör att Östersjöns ekosystem är extra känslig för påverkan i och med att flera av de arter som lever här lever nära eller på gränsen av vad de klarar av. De är mer eller mindre stressade av salthalten och är därför ofta känsligare än när de förekommer i sin ursprungsmiljö. Ökad konkurrens från främmande arter kan bidra till att de ursprungliga arterna får svårare att överleva. Under senare år har två främmande arter, havsborstmasken Marenzelleria och tusensnäckan Potamopyrgus antipodarum blivit allt vanligare på bottnarna i östgötaskärgården. Dessa arter är särskilt vanliga i länets innerskärgårdar och det finns risk att de tränger ut inhemska bottendjur.Eftersom havsborstmasken Marenzelleria kan gräva mycket djupa gångar i bottnarna kan de bidra till ökad frisättning av miljögifter och näringsämnen som länge legat begravda i sedimenten. Tillgången på grundvatten är generellt god i länet, men olika former av mänsklig påverkan riskerar att förorena grundvattnet. Övervakningen av grundvattenmagasin är relativt nystartad och vi vet ännu relativt lite om grundvattnets kvalitet. De undersökningar som Länsstyrelsen hittills genomfört har visat spår av både organiska föroreningar och tungmetaller i några av länets grundvattenmagasin.En del av de problem som finns i grundvattnet, som till exempel höga halter av radon, fluorid och uran, kan dock kopplas till naturliga förekomster i berggrunden. Överuttag av grundvatten i kust och skärgårdsområden kan leda till saltvatteninträngning. Eftersom större delen av Östergötland har varit täckt av hav kan grundvattnet även vara påverkat av relikt (gammalt) saltvatten.Den här rapporten är en del i Länsstyrelsens satsning för att öka kunskapen och medvetenheten om länets vattenmiljöer. Tillsammans kan vi verka för att vårda, bevara och förbättra miljötillståndet i våra unika vattenmiljöer.Det pågår ett intensivt förbättringsarbete på flera nivåer, såväl internationellt som nationellt. På den lokala nivån finns ett stort intresse och engagemang inom länets nio lokala samverkansforum, de s.k. vattenråden.Det har aldrig funnits så stor chans att påverka vattenmiljön som nu!
|
|
| 5. |
|
|
| 6. |
- Bohlin, Alexis, et al.
(författare)
-
Pure rotational CARS measurements of temperature and O2-concentration in a low swirl turbulent premixed flame
- 2013
-
Ingår i: Proceedings of the Combustion Institute. - : Elsevier BV. - 1540-7489. ; 34, s. 3629-3636
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedTemperature and relative O-2-concentrations have been measured using pure rotational coherent anti-Stokes Raman spectroscopy (RCARS) in a low swirl turbulent premixed flame. This lean flame burning methane has previously been investigated using laser diagnostic techniques and numerical modeling of flame characteristics. In the present work, single-shot RCARS measurements were performed and analysed statistically to obtain temperature and O-2-concentration probability density functions. The results were compared with large eddy simulations (LES) showing fairly good agreement. The rotational CARS technique was successfully applied in the whole range of temperatures (300-1700 K) and relative O-2-concentrations (9-21%), and based on the simultaneous measurements of temperature and O-2-concentration an improved understanding of the reaction progress and air entrainment from the surroundings can be achieved. From the evaluated O-2-concentration, the H2O mole fraction could be estimated, which subsequently made an important thermometric correction possible of up to similar to 40 K at 1700 K by inclusion of N-2-H2O line-broadening coefficients in the theoretical spectral calculations. Spatial averaging effects were observed in a fraction of spectra where both hot and cold spectral envelopes were detected, most often with corresponding peaks displaced relative to each other. The large range of CARS signal intensities (about 3 orders of magnitude) when intermittently probing low and high temperature gases was dealt with by using a multi-track function of the CCD camera that increased the dynamic range. Merits and limitations of pure rotational CARS for diagnostics in turbulent flames are discussed and comparison is made with vibrational CARS. (C) 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
|
|
| 7. |
- Carlsson, Anders, et al.
(författare)
-
A new scolenaspidid (Osteostraci) from the lower Devonian of Podolia, Ukraine
- 2008
-
Ingår i: Paläontologische Zeitschrift. - 0031-0220. ; 82:3, s. 314-323
-
Tidskriftsartikel (refereegranskat)abstract
- A new osteostracan genus and species. Victoraspis longicornualis n. gen., n. sp., is described based on material from Rakovets', present day Ukraine. This new taxon shares characters with the two genera Stensiopelta DENISON, 1951 and Zychaspis JANVIER, 1985. A phylogenetic analysis supports the position of Victoraspis as the sister group to a monophyletic Stensiopelta, while the interrelationships of the various species of Zychaspis are poorly resolved. A morphometric analysis is carried out in an attempt to further resolve the taxonomic affinity. This analysis groups all examined Zychaspis species closely together, and further supports the establishment of Victoraspis as separate, genus.
|
|
| 8. |
|
|
| 9. |
- Carlsson, Ella, et al.
(författare)
-
FIELD STUDIES OF GULLIES AND PINGOS ON SVALBARD – A MARTIAN ANALOG.
- 2008
-
Ingår i: European Planetary Science Congress, 21-26 September 2008. ; 3
-
Konferensbidrag (refereegranskat)abstract
- The gully systems on Mars have been found to superpose young geological surfaces such as dunes and thermal contraction polygons. This in combination with the general absence of superimposed impact craters suggest that the gullies are relatively recent geological formations. The observed gullies display a wide set of morphologies ranging from features seemingly formed by fluvial erosion to others pointing to dry landslide processes. A recent discovery suggests that this is an ongoing process, which appears to occur even today. Several formation mechanisms have been proposed for the Martian gullies, such as liquid carbon dioxide reservoirs, shallow liquid water aquifer, melting ground ice, dry landslide, snow melt and deep liquid water aquifer. However, none of these models can alone explain all the gullies discovered on Mars. So far Martian gullies have been studied only from orbit via remote sensing data. Hydrostatic pingos are perennial ice-cored mounds that may reach an elongated or circular radius of approximately 150 m. They are found in periglacial environments where they are formed by freezing processes in the continuous permafrost. The pingos go through different evolutionary stages as they mature, where the final stage leaves an annular rim left by the collapse of the summit. Images from the High Resolution Imaging Science Experiment (HiRISE) show small fractured mounds in the Martian mid-latitudes. Even though some differences are observed, the best terrestrial analogues for the observed mound morphology are pingos. Gullies and pingos found in Arctic climates on Earth could be an analog for the Martian ones. A comparative analysis might help to understand the formation mechanisms of the Martian pingos and gullies and their possible eroding agent.
|
|
| 10. |
- Carlsson, Erik, et al.
(författare)
-
Geochemistry of the infiltrating water in the vadose zone of a remediated tailings impoundment, Kristineberg, northern Sweden
- 2003
-
Ingår i: Applied Geochemistry. - 0883-2927 .- 1872-9134. ; 18:5, s. 659-674
-
Tidskriftsartikel (refereegranskat)abstract
- At the remediated tailings Impoundment 1 at Kristineberg, Northern Sweden, installations of tension lysimeters were performed in the protective cover (10, 50, and 100 cm), in the oxidised tailings (150 cm), in the unoxidised secondarily enriched tailings (200 cm) and in the unoxidised tailings (260 cm). The lysimeters in the till protective cover contained relatively low concentrations of most elements. After infiltration through the sealing layer, consisting of 0.3 m compacted clayey till, pH decreased and conductivity, together with the concentrations of several major and trace elements, increased significantly. In the lysimeters installed in the tailings at depths of 150 and 200 cm average pH decreased to 3.4 at 150 cm and 3.2 at 200 and average conductivity increased to 2.9 mS/cm. Elements such as Al, Cd, Co, Fe, Mn, Mo, Ni,Pb, S, Si and Zn had the highest concentrations in the lysimeter at 200 cm depth. Examples of concentration averages for this lysimeter are Cd 600 μg/L, Fe 1500 mg/L, Mn 11 mg/L, Ni 1.06 μg/L, S 1800 mg/L, and Zn 190 mg/L. Between the depths of 200 and 260 cm the concentration of most elements decreased. The increase between the lysimeters at the depths of 150 and 200 cm can be explained by remobilization of secondarily retained oxidation products as well as from the continued oxidation. The decrease between the second and the third lysimeters is interpreted as co-precipitation with different Fe oxyhydroxides as well as adsorption onto secondarily formed minerals and primary mineral surfaces. Calculations of saturation indices indicate that several different hydroxides might precipitate at this level. This retainment takes place mainly due to the increase in pH. The pH increases from 3.2 up to 4-4.4 in this depth interval. Between the deepest lysimeter and the groundwater table, the element concentrations probably decrease even further. pH increases to 5-6.5 in the groundwater. Most of the pre-remediation oxidation products that are secondarily retained above or below the oxidation front and are released by the small amount of infiltrating water together with the present oxidation products are retained again during continued transport downwards. If the depth to the groundwater table is large enough, most of the metals released by the infiltrating water and the diffusing O2 do not reach the groundwater.
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
- Carlsson, Henning
(författare)
-
Detailed Numerical Simulations of Turbulent Premixed Flames at Moderate and High Karlovitz Numbers
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In generally accepted and applied flamelet combustion models, a turbulent flame is mainly assumed distorted by the large-scale turbulence eddies, whereas small-scale turbulence effects on the local flamelet structures are neglected. However, in a lot of industrial applications rather high turbulent intensities are often imposed, which induce turbulence scales at ranges smaller than the flame thickness. Flame/turbulence interaction appears quite different at these small scales, which is why improvement of the combustion models is required to account for these phenomena. In this thesis, direct numerical simulations (DNS) and large eddy simulations (LES) have been utilized for studies of lean premixed turbulent reactive flows at various turbulent intensities. DNS has been applied for detailed studies of flame-turbulence interaction to investigate flame structures and detailed chemistry effects at high Karlovitz numbers. Intensified convective-diffusive transport within the fine reaction zone layers is observed which is found to significantly alter the chemical pathway with, e.g., intensified heat release rate at low temperatures. Based on these observations a categorization, supplementary to the conventional one, is proposed, which is able to incorporate detailed chemistry effects into the classification of turbulent premixed flames at high Karlovitz numbers. The effect of differential diffusion was found significant, both globally (in terms of the fuel diffusion effect) and locally (in terms of the radical diffusion effect), also in the distributed reaction zone regime. LES was employed for a low swirl stabilized flame utilizing a flamelet combustion model approach. A dynamic modeling approach to incorporate sensitivity to local variations in the subgrid scale flame wrinkling was implemented and validated. The simulations showed high sensitivity of the prediction of turbulent flame fluctuations as well as ambient air entrainment rate into burned gases to inflow conditions and operating conditions. Lower sensitivity was found to domain size and combustion model. Overall the model results showed good agreement with the velocity and scalar validation data in the thin reaction zone regime. In order to analyze the influence of frequency specific coherent structures on the flame dynamics extended dynamic mode decomposition was performed which was able to delineate the effects of the inner and outer shear layer vorticity on the flame stabilization.
|
|
| 14. |
- Carlsson, Henning, et al.
(författare)
-
Direct numerical simulation of lean premixed CH4/air and H-2/air flames at high Karlovitz numbers
- 2014
-
Ingår i: International Journal of Hydrogen Energy. - : Elsevier BV. - 1879-3487 .- 0360-3199. ; 39:35, s. 20216-20232
-
Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional direct numerical simulation with detailed chemical kinetics of lean premixed CH4/air and H-2/air flames at high Karlovitz numbers (Ka similar to 1800) is carried out. It is found that the high intensity turbulence along with differential diffusion result in a much more rapid transport of H radicals from the reaction zone to the low temperature unburned mixtures (similar to 500 K) than that in laminar flamelets. The enhanced concentration of H radicals in the low temperature zone drastically increases the reaction rates of exothermic chain terminating reactions (e.g., H + O-2+M = HO2 + M in lean H-2/air flames), which results in a significantly enhanced heat release rate at low temperatures. This effect is observed in both CH4/air and H-2/air flames and locally, the heat release rate in the low temperature zone can exceed the peak heat release rate of a laminar flamelet. The effects of chemical kinetics and transport properties on the H-2/air flame are investigated, from which it is concluded that the enhanced heat release rate in the low temperature zone is a convection-diffusion-reaction phenomenon, and to obtain it, detailed chemistry is essential and detailed transport is important. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
- Carlsson, Henning, et al.
(författare)
-
Flame structure analysis for categorization of lean premixed CH4/air and H-2/air flames at high Karlovitz numbers: Direct numerical simulation studies
- 2015
-
Ingår i: Proceedings of the Combustion Institute. - : Elsevier BV. - 1540-7489. ; 35, s. 1425-1432
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents direct numerical simulation studies of lean CH4/air and H-2/air flames at high Karlovitz numbers utilizing detailed chemical kinetic mechanisms. Identical Karlovitz numbers are applied to the two flames; however, as the interaction of high turbulence intensity small scale structures with the reaction zones is considered, a significant difference in the effect of the turbulence structures on the inner reaction layer is observed. The heat release rate layer as well as layers of different species reaction rates is found to be more distributed for the H-2/air flame compared with those in the CH4/air flame, owing to the difference in the Kolmogorov length scale and the differential diffusion effects. A modified, species-specific Karlovitz number is proposed, where the chemical time scale in the definition is a characteristic speciesspecific chemical time scale, which is obtained from stationary 1D simulations. The difference between the two flames for different intermediate species corresponds well to the difference in the obtained species-specific Karlovitz numbers. A validation study of the species-specific Karlovitz number is also conducted, where a turbulent effective chemical time scale is quantified for different intermediate species from instantaneous data sets. It is shown that in the preheat zone and reaction zone of the flame, the ratio between the laminar and turbulent chemical time scales of intermediate species corresponds well to the species-specific Karlovitz numbers for the two different flames. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
|
|
| 18. |
|
|
| 19. |
- Carlsson, Henning, et al.
(författare)
-
Numerical and experimental study of flame propagation and quenching of lean premixed turbulent low swirl flames at different Reynolds numbers
- 2015
-
Ingår i: Combustion and Flame. - : Elsevier BV. - 0010-2180. ; 162:6, s. 2582-2591
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a joint experimental and large eddy simulation (LES) study of lean premixed low swirl stabilized methane/air flames at different Reynolds numbers (Re similar to 20,000-100,000). The aims are to investigate the sensitivity of the structures and dynamics of low swirl flames to the inflow boundary conditions and to evaluate the capability of an LES flamelet model in predicting the stabilization and local extinction of the flames. Chemiluminescence measurements are carried out for Re - 20,000-50,000 and further detailed oxygen concentration and temperature fields are measured using rotational coherent anti-Stokes Raman spectroscopy (RCARS) for Re - 20,000 and 30,000 along the centerline of the burner and at various radial positions at different heights above the burner. The data are used first for validation of the combustion LES model employed in the numerical simulations, and then the RCARS and LES results are used to delineate the effect of ambient air entrainment on the flame structure at various burner exit velocities. A three-scalar flamelet model based on a level-set G-equation shows excellent predictions of the lift-off positions and the structures of the flames, including quenching at the trailing edge of the flame. The results show that the flame lift-off height varies only slightly when the burner exit velocity is increased, which is consistent with a shear-layer flame stabilization mechanism reported previously. The volume of the flame decreases substantially with increasing burner exit velocity at relatively low Reynolds numbers, as a result of flame quenching at the trailing edge of the flame caused by entrainment of the ambient air into the fuel/air stream and the flame itself. At high Reynolds numbers the flame structures become fairly self-similar with the flame volume nearly independent of the Reynolds number. (C) 2015 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
|
|
| 20. |
- Carlsson, Magnus, 1975-, et al.
(författare)
-
Are Politicians Biased Against Ethnic Minority Candidates? : Experimental Evidence from Norway
- 2024
-
Ingår i: Journal of Politics. - : University of Chicago Press. - 0022-3816 .- 1468-2508. ; 86:1, s. 126-140
-
Tidskriftsartikel (refereegranskat)abstract
- To what extent is the underrepresentation of ethnic minorities in politics due to ethnic bias? While this question has interested researchers for a long time, direct evidence of ethnic bias in party-controlled nomination processes is scarce. We conducted survey experiments with politicians and voters in Norway, where parties control the nomination process, to examine bias against ethnic minority candidates. The politicians evaluated candidate profiles with randomly assigned information about the candidates’ ethnic backgrounds. Contrary to our expectations, we find that ethnic minority candidates receive higher quality scores and better rankings than ethnic majority candidates. However, the results of a list experiment with voters show that a substantial share of right-wing voters has reservations against voting for a party list with many ethnic minority candidates. Consequently, our study suggests that while the political elite wants ethnically diverse party lists, for some parties, such lists might have an electoral cost.
|
|
| 21. |
- Carlsson, Magnus, 1975-, et al.
(författare)
-
Gender Bias in Academic Recruitment? : Evidence from a Survey Experiment in the Nordic Region
- 2021
-
Ingår i: European Sociological Review. - : Oxford University Press. - 0266-7215 .- 1468-2672. ; 37:3, s. 399-410
-
Tidskriftsartikel (refereegranskat)abstract
- Gender disparities in top-level academic positions are persistent. However, whether bias in recruitment plays a role in producing these disparities remains unclear. This study examines the role of biasin academic recruitment by conducting a large-scale survey experiment among faculty in Economics,Law, Physics, Political Science, Psychology, and Sociology from universities in Iceland, Norway, andSweden. The faculty respondents rated CVs of hypothetical candidates—who were randomlyassigned either a male or a female name—for a permanent position as an Associate Professor in theirdiscipline. The results show that, despite the underrepresentation of women in all fields, the femalecandidates were viewed as both more competent and more hireable compared to their malecounterparts. Having children or a stronger CV do not change the overall result. Consequently, biasedevaluations of equally qualified candidates to Associate Professor positions do not seem to be the keyexplanation of the persistent gender gap in academia in the Nordic region.
|
|
| 22. |
|
|
| 23. |
- Henning, Petra, 1974, et al.
(författare)
-
Adenovirus type 5 fiber knob domain has a critical role in fiber protein synthesis and encapsidation
- 2006
-
Ingår i: JOURNAL OF GENERAL VIROLOGY. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 87, s. 3151-3160
-
Tidskriftsartikel (refereegranskat)abstract
- Adenovirus serotype 5 (Ad5) vectors carrying knobless fibers designed to remove their natural tropism were found to have a lower fiber content than recombinant Ad5 with wild-type (WT) capsid, implying a role for the knob-coding sequence or/and the knob domain in fiber encapsidation. Experimental data using a variety of fiber gene constructs showed that the defect did not occur at the fiber mRNA level, but at the protein level. Knobless fiber proteins were found to be synthesized at a significant slower rate compared with knob-carrying fibers, and the trimerization process of knobless fibers paralleled their slow rate of synthesis. A recombinant Ad5 diploid for the fiber gene (referred to as Ad5/R7-ZZwt/E1 : WT-fiber) was constructed to analyse the possible rescue of the knobless low-fiber-content phenotype by co-expression of WT fiber. Ad5/R7-ZZwt/E1 : WT-fiber contained a knobless fiber gene in its natural location (L5) in the viral genome and an additional WT fiber gene in an ectopic position in E1. Knobless fiber was still synthesized at low levels compared with the co-expressed E1 : WT fiber and the recovery of the two fiber species in virus progeny reflected their respective amounts in the infected cells. Our results suggested that deletion of the fiber knob domain had a negative effect on the translation of the fiber mRNA and on the intracellular concentration of fiber protein. They also suggested that the knob control of fiber protein synthesis and encapsidation occurred as aciseffect, which was not modified by WT fiber protein providedin transby the same Ad5 genome.
|
|
| 24. |
- Holmström, Henning, et al.
(författare)
-
Geochemical investigations of sulfide-bearing tailings at Kristineberg, northern Sweden, a few years after remediation
- 2001
-
Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 273:1-3, s. 111-113
-
Tidskriftsartikel (refereegranskat)abstract
- In the Kristineberg mining area in northern Sweden, massive, pyrite-rich Zn-Cu ores are intercalated in ca. 1.9 Ga volcano-sedimentary rocks. Investigations of a tailings impoundment remediated by means of both till coverage and raising the groundwater table have been undertaken. The aim of the study was to characterise the tailings with respect to mineralogy, the chemical composition of both the tailings and the pore water, and to try to identify the significant reactions that may have occurred before and after remediation. It was found that the oxidation front had reached down to depths of between approximately 0.1 and 1.15 m before remediation. The oxidation of sulfides has produced high concentrations of some metals in the pore water; up to 26, 16, 4.1, 2.7 and 82 mg/l have been measured for Al, Mn, Fe and Zn, respectively. Concentrations of metals such as Cd, Co, Cu, Ni and Pb are lower, with average concentrations of 18.4, 83.8, 45, 79.6 and 451 μg/l, respectively. Higher concentrations of major elements such as Ca, Fe, Mn, Mg and S have been measured at depth in pore water than at shallower levels. This is probably caused by flush out of elements after remediation and vertical transport from the upper parts before remediation. The pH is relatively high, approximately 5.5 at most depths in the tailings, except in and around the former oxidation zone where it is lower, and where the highest dissolved concentrations of elements such as As, Cd, Co, Cu, Pb and Zn occur. This is probably due to the release of metals secondarily retained below the oxidation front prior to the remediation. Since the groundwater table is raised, the groundwater reaches the retained metals, which leads to desorption of metals and dissolution of secondary minerals.
|
|
| 25. |
- Nilsson, Thommie, et al.
(författare)
-
Structures of turbulent premixed flames in the high Karlovitz number regime – DNS analysis
- 2018
-
Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 216, s. 627-638
-
Tidskriftsartikel (refereegranskat)abstract
- Lean premixed turbulent methane-air flames have been investigated using direct numerical simulations (DNS) for different Karlovitz numbers (Ka), ranging from 65 to 3350. The flames are imposed to a high intensity small-scale turbulent environment, corresponding to high Ka conditions, and the effect on the flame structure is investigated during the transition from initial laminar flame to highly distorted turbulent flame. The focus is on the internal structure of different sub-layers of these flames. The preheat layer, fuel consumption layer and oxidation layer are characterized by the distribution of formaldehyde, the fuel consumption rate and the CO consumption rate, respectively. Different measures that quantify sub-layer thickness for turbulent flames have been defined and analyzed. The flame brush is broadened with time while the local thickness (excluding large scale wrinkling) of all three layers initially show thinning due to the interaction of the flame with the turbulent flow field. As time passes, the local thickness of the preheat layer and fuel consumption layer are restored while the oxidation layer remains thinned due to suppression of CO consuming reactions. As Ka increases there is an increasing probability of finding thinned, large gradient regions in each of these sub-layers. The contribution to the evolution of flame thickness from normal strain rate, chemical reaction and normal and tangential diffusion is analyzed in terms of a gradient transport equation. The relative size of the terms changes as Ka increase and, in particular, the term due to chemical reactions loses its relative significance. The observed thinning of the local flame structure is attributed to the preferential alignment of the flame normal with the compressive strain rate eigenvectors. Such alignment provides a mechanism for the flame thinning, consistent with the behavior of non-reacting scalars. A preferred angle of about 20 degrees is observed between the flame normal and the compressive strain rate eigenvector.
|
|
| 26. |
- Savre, Julien, et al.
(författare)
-
Turbulent Methane/Air Premixed Flame Structure at High Karlovitz Numbers
- 2013
-
Ingår i: Flow, Turbulence and Combustion. - : Springer Science and Business Media LLC. - 1573-1987 .- 1386-6184. ; 90:2, s. 325-341
-
Tidskriftsartikel (refereegranskat)abstract
- 2D Direct Numerical Simulations of methane/air turbulent premixed flames at initial Karlovitz numbers ranging from 600 to 9500 are performed. Instantaneous results are then extracted and analyzed with a focus on the inner flame structure. Snapshots reveal that the distributed reaction zone regime, theoretically reached around Ka a parts per thousand aEuro parts per thousand 100, is not attained before Ka a parts per thousand aEuro parts per thousand 2000. A correction of the definition of Ka is proposed in order to account for gas expansion across the flame, and is found to be consistent with the previous observations. The fuel-consumption zone is shown to be highly affected by turbulence and the characteristics of flames developing at lower Ka cannot be seen: the reaction zone is indeed strongly stretched and curved by intense turbulence leading to the formation of large protruding structures. In addition, the heat release rate layer is found to be broader and more distributed than at lower Ka as small turbulent eddies are able to survive inside it. No local flame quenching is however noticed. A statistical analysis of the distributed flame highlighted three major features characterizing this regime: significant broadening of the whole flame results from the presence of small eddies inside the reaction zone, temperature evolves linearly with respect to the progress variable and minor species peak mass fractions are lower than in a laminar flame. These results have important consequences for turbulent combustion modelling of flames in the distributed combustion regime.
|
|
| 27. |
- Walters, R G, et al.
(författare)
-
A new highly penetrant form of obesity due to deletions on chromosome 16p11.2.
- 2010
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 463:7281, s. 671-5
-
Tidskriftsartikel (refereegranskat)abstract
- Obesity has become a major worldwide challenge to public health, owing to an interaction between the Western 'obesogenic' environment and a strong genetic contribution. Recent extensive genome-wide association studies (GWASs) have identified numerous single nucleotide polymorphisms associated with obesity, but these loci together account for only a small fraction of the known heritable component. Thus, the 'common disease, common variant' hypothesis is increasingly coming under challenge. Here we report a highly penetrant form of obesity, initially observed in 31 subjects who were heterozygous for deletions of at least 593 kilobases at 16p11.2 and whose ascertainment included cognitive deficits. Nineteen similar deletions were identified from GWAS data in 16,053 individuals from eight European cohorts. These deletions were absent from healthy non-obese controls and accounted for 0.7% of our morbid obesity cases (body mass index (BMI) >or= 40 kg m(-2) or BMI standard deviation score >or= 4; P = 6.4 x 10(-8), odds ratio 43.0), demonstrating the potential importance in common disease of rare variants with strong effects. This highlights a promising strategy for identifying missing heritability in obesity and other complex traits: cohorts with extreme phenotypes are likely to be enriched for rare variants, thereby improving power for their discovery. Subsequent analysis of the loci so identified may well reveal additional rare variants that further contribute to the missing heritability, as recently reported for SIM1 (ref. 3). The most productive approach may therefore be to combine the 'power of the extreme' in small, well-phenotyped cohorts, with targeted follow-up in case-control and population cohorts.
|
|
| 28. |
- Widerlund, Anders, et al.
(författare)
-
Laboratory study of calcite-gypsum sludge-water interactions in a flooded tailings impoundment at the Kristineberg Zn-Cu mine, northern Sweden
- 2005
-
Ingår i: Applied Geochemistry. - : Elsevier BV. - 0883-2927 .- 1872-9134. ; 20:5, s. 973-987
-
Tidskriftsartikel (refereegranskat)abstract
- Due to liming of acid mine drainage, a calcite–gypsum sludge with high concentrations of Zn (24,400 ± 6900 μg g−1), Cu (2840 ± 680 μg g−1) and Cd (59 ± 20 μg g−1) has formed in a flooded tailings impoundment at the Kristineberg mine site. The potential metal release from the sludge during resuspension events and in a long-term perspective was investigated by performing a shake flask test and sequential extraction of the sludge. The sequentially extracted carbonate and oxide fractions together contained 97% of the total amount of Cd, Co, Cu, Ni, Pb and Zn in the sludge. The association of these metals with carbonates and oxides appears to result from sorption and/or coprecipitation reactions at the surfaces of calcite and Fe, Al and Mn oxyhydroxides forming in the impoundment. If stream water is diverted into the flooded impoundment, dissolution of calcite, gypsum and presumably also Al oxyhydroxides can be expected during resuspension events. In the shake flask test (performed at a pH of 7–9), remobilisation of Zn, Cu, Cd and Co from the sludge resulted in dissolved concentrations of these metals that were significantly lower than those predicted to result from dissolution of the carbonate fraction of the sludge. This may suggest that cationic Zn, Cu, Cd and Co remobilised from dissolving calcite, gypsum and Al oxyhydroxides were readsorbed onto Fe oxyhydroxides remaining stable under oxic conditions. In a long-term perspective (102 a), 97% of the Cd, Co, Cu, Ni, Pb and Zn content of the sludge potentially is available for release by dissolution of calcite and reductive dissolution of Fe oxyhydroxides if the sludge is subject to a soil environment with lower dissolved Ca concentrations, pH and redox than in the impoundment.
|
|
| 29. |
- Ögren, Magnus, 1977-, et al.
(författare)
-
Numerical simulations of NMR relaxation in chalk using local Robin boundary conditions
- 2019
-
Ingår i: Journal of magnetic resonance. - : Elsevier. - 1090-7807 .- 1096-0856. ; 308
-
Tidskriftsartikel (refereegranskat)abstract
- The interpretation of nuclear magnetic resonance (NMR) data is of interest in a number of fields. In Ögren [Eur. Phys. J. B (2014) 87: 255] local boundary conditions for random walk simulations of NMR relaxation in digital domains were presented. Here, we have applied those boundary conditions to large, three-dimensional (3D) porous media samples. We compared the random walk results with known solutions and then applied them to highly structured 3D domains, from images derived using synchrotron radiation CT scanning of North Sea chalk samples. As expected, there were systematic errors caused by digitalization of the pore surfaces so we quantified those errors, and by using linear local boundary conditions, we were able to significantly improve the output. We also present a technique for treating numerical data prior to input into the ESPRIT algorithm for retrieving Laplace components of time series from NMR data (commonly called T-inversion).
|
|
| 30. |
|
|
| 31. |
|
|
| 32. |
|
|
