| 21. |
- Glasser, Neil, et al.
(författare)
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The glacial geomorphology and Pleistocene history of South America between 38 degrees S and 56 degrees S
- 2008
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Ingår i: QUATERNARY SCIENCE REVIEWS. - : Elsevier. - 0277-3791. ; 27:3-4, s. 365-390
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents new mapping of the glacial geomorphology of southern South America between latitudes 38 degrees S and 56 degrees S, approximately the area covered by the former Patagonian Ice Sheets. Glacial geomorphological features, including glacial lineations, moraines, meltwater channels, trimlines, sandur and cirques, were mapped from remotely sensed images (Landsat 7 ETM +, pan-sharpened Landsat 7 and ASTER). The landform record indicates that the Patagonian Ice Sheets consisted of 66 main outlet glaciers, together with numerous local cirque glaciers and independent ice domes in the surrounding mountains. In the northern part of the mapped area, in the Chilean Lake District (38-42 degrees S), large piedmont glaciers developed on the western side of the Andes and the maximum positions of these outlet glaciers are, in general, marked by arcuate terminal moraines. To the east of the Andes between 38 degrees S and 42 degrees S, outlet glaciers were more restricted in extent and formed "alpine-style" valley glaciers. Along the eastern flank of the Andes south of similar to 45 degrees S a series of large fast-flowing outlet glaciers drained the ice sheet. The location of these outlet glaciers was topographically controlled and there was limited scope for interactions between individual lobes. West of the Andes at this latitude, there is geomorphological evidence for an independent ice cap close to sea level on the Taitao Peninsula. The age of this ice cap is unclear but it may represent evidence of glacier growth during the Antarctic Cold Reversal and/or Younger Dryas Chronozone. Maximum glacier positions are difficult to determine along much of the western side of the Andes south of 42 degrees S because of the limited land there, and it is assumed that most of these glaciers had marine termini. In the south-east of the mapped area, in the Fuegan Andes (Cordillera Darwin), the landform record provides evidence of ice-sheet initiation. By adding published dates for glacier advances from the literature we present maps of pre-Last Glacial Maximum (LGM) glacier extent, LGM extent and the positions of other large mapped moraines younger than LGM in age. A number of large moraines occur within the known LGM limits. The age of these moraines is unknown but, since many of them lie well outside the established maximum Neoglacial positions, the possibility that they reflect a return to glacial climates during the Younger Dryas Chronozone or Antarctic Cold Reversal cannot be discounted.
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| 22. |
- Goodfellow, Bradley, et al.
(författare)
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Deciphering a non-glacial/glacial landscape mosaic in the northern Swedish mountains
- 2008
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Ingår i: Geomorphology. - : Elsevier BV. - 0169-555X. ; 93:3-4, s. 213-232
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Tidskriftsartikel (refereegranskat)abstract
- Relict surfaces contain information on past surface processes and long-term landscape evolution. A detailed investigation of relict non-glacial surfaces in a formerly glaciated mountain landscape of northern Sweden was completed, based on interpretation of colour infrared aerial photographs, analysis in a GIS, and fieldwork. Working backwards from landscape to process, surfaces were classified according to large- and small-scale morphologies that result from the operation of non-glacial processes, the degree of weathering, regolith characteristics, and the style of glacial modification. Surfaces were also compared in the GIS according to elevation, slope angle, and bedrock lithology. The study revealed five types of relict non-glacial surfaces but also two types of extensively weathered glacial surfaces that were transitional to relict non-glacial surfaces, illustrating spatially variable processes and rates of non-glacial and glacial landscape evolution. Rather than being static preglacial remnants, relict non-glacial surfaces are dynamic features that have continued to evolve during the Quaternary. The classification provides hypotheses for landscape evolution that can be field tested through, for example, terrestrial cosmogenic nuclide studies and geochemical analyses of fine matrix materials. The classification may be applicable to relict non-glacial surfaces in other formerly glaciated landscapes
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| 23. |
- Goodfellow, Bradley, et al.
(författare)
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Relict non-glacial surfaces in formerly glaciated landscapes: dynamic landform systems?
- 2007
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Ingår i: Geophysical Research Abstracts.
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Konferensbidrag (refereegranskat)abstract
- Relict non-glacial surfaces occur within many formerly glaciated landscapes and containimportant information on past surface processes and long-term landscape evolution(Goodfellow, 2007). While cosmogenic dating has confirmed the antiquity ofrelict non-glacial surfaces, the processes that contribute to their evolution and, consequently,the time scales over which they develop remain poorly understood. Of particularimportance is the possibility that relict non-glacial surfaces may provide geomorphicmarkers for the reconstruction of preglacial landscapes, which would allowsubsequent glacial erosion to be quantified. Furthermore, relict non-glacial surfacesmay also hold information on preglacial and interglacial environmental conditions.An investigation of relict non-glacial surfaces was undertaken through remote sensing,mapping and analysis of surfaces in a GIS, and regolith studies involving cosmogenicdating-, grain size-, X-ray diffraction-, and X-ray fluorescence analyses. Onthe basis of these on-going studies, we show that depending on spatial variables suchas bedrock lithology, slope, regolith thickness, and the abundance of fine matrix andwater some surfaces are denuding very slowly, while others display more rapid denudation.High spatial variability in denudation rates results in changing surface morphologiesover time. Rather than being static preglacial remnants, relict non-glacialsurfaces are dynamic features that have evolved during the Quaternary. While reconstructionsof preglacial landscapes and subsequent quantifications of glacial erosionfrom relict non-glacial surfaces remain valid, the Quaternary evolution of these surfacesshould also be considered.Goodfellow B.W., 2007. Relict non-glacial surfaces in formerly glaciated landscapes.Earth-Science Reviews, 80(1-2): 47-73.
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| 24. |
- Goodfellow, Bradley, et al.
(författare)
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Relict non-glacial surfaces in formerly glaciated landscapes: dynamic landform systems?
- 2007
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Ingår i: Quaternary International.
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Konferensbidrag (refereegranskat)abstract
- Relict non-glacial surfaces occur within many formerly glaciated landscapesand contain important information on past surface processes and long-term landscape evolution. While cosmogenic dating has confirmedthe antiquity of relict non-glacial surfaces, the processes that contribute to their evolution and, consequently, the time scales over which they develop remain poorly understood. Of particular importanceis the possibility that relict non-glacial surfaces may provide geomorphic markers for the reconstruction of preglacial landscapes, which would allow subsequent glacial erosion to be quantified. Furthermore,relict non-glacial surfaces may also hold information on preglacialand interglacial environmental conditions. An investigation of relict non-glacial surfaces was undertaken through remote sensing, mapping and analysis of surfaces in a GIS, and regolith studies involvingcosmogenic dating-, grain size-, X-ray diffraction-, and X-ray fluorescenceanalyses. On the basis of these on-going studies, we show that depending on spatial variables such as bedrock lithology, slope, regolith thickness, and the abundance of fine matrix and water some surfaces are denuding very slowly, while others display more rapid denudation. High spatial variability in denudation rates results in changing surface morphologies over time. Rather than being static preglacialremnants, relict non-glacial surfaces are dynamic features that have evolved during the Quaternary. While reconstructions of preglaciallandscapes and subsequent quantifications of glacial erosion from relict non-glacial surfaces remain valid, the Quaternary evolution of these surfaces should also be considered.
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| 25. |
- Goodfellow, Bradley W., 1971-
(författare)
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Relict non-glacial surfaces and autochthonous blockfields in the northern Swedish mountains
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Relict non-glacial surfaces occur in many formerly glaciated landscapes, where they represent areas that have escaped significant glacial modification. Frequently distinguished by blockfield mantles, relict non-glacial surfaces are important archives of long-term weathering and landscape evolution processes. The aim of this thesis is to examine the distribution, weathering, ages, and formation of relict non-glacial surfaces in the northern Swedish mountains. Mapping of surfaces from aerial photographs and analysis in a GIS revealed five types of relict non-glacial surfaces that reflect differences in surface process types or rates according to elevation, gradient, and bedrock lithology. Clast characteristics and fine matrix granulometry, chemistry, and mineralogy reveal minimal chemical weathering of the blockfields. Terrestrial cosmogenic nuclides were measured in quartz samples from two blockfield-mantled summits and a numerical ice sheet model was applied to account for periods of surface burial beneath ice sheets and nuclide production rate changes attributable to glacial isostasy. Total surface histories for each summit are almost certainly, but not unequivocally, confined to the Quaternary. Maximum modelled erosion rates are as low as 4.0 mm/kyr, which is likely to be near the low extreme for relict non-glacial surfaces in this landscape. The blockfields of the northern Swedish mountains are Quaternary features formed through subsurface physical weathering processes. While there is no need to appeal to Neogene chemical weathering to explain blockfield origins, these surfaces have remained continuously regolith-mantled and non-glacial since their inception. Polygenetic surface histories are therefore indicated, where the large-scale surface morphologies are potentially older than their regolith mantles.
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| 26. |
- Grönlund, Hans, et al.
(författare)
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Low levels of IgM antibodies against phosphorylcholine predict development of acute myocardial infarction in a population-based cohort from northern Sweden.
- 2009
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Ingår i: European Journal of Cardiovascular Prevention & Rehabilitation. - : Sage. - 1741-8267 .- 1741-8275. ; 16:3, s. 382-386
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Phosphorylcholine (PC) is one important epitope on oxidized low-density lipoprotein that may play an important role by contributing to the atherogenicity of oxidized low-density lipoprotein. IgM antibodies against PC (anti-PC) are present ubiquitously in the population as natural antibodies. We here determine the association between anti-PC and incidence of myocardial infarction (MI). METHODS: We studied 462 incident cases of first events of MI and 888 age-matched and sex-matched controls identified through 13 years of follow-up (1987-1999) of participants in a population-based study from northern Sweden. Relative risks (RRs) with 95% confidence intervals (CIs) of incident MI with adjustments for age, sex, geographical region, hypertension, diabetes, BMI, smoking habits, s-cholesterol and high-sensitivity C-reactive protein were determined. Anti-PC levels were measured by enzyme-linked immunoassay. RESULTS: Low anti-PC values were associated with increased risk of MI. Significant associations were found for values below 26.8 U/ml, corresponding to the lowest 25th percentile, and the highest association was seen below 16.9 U/ml. These results remained almost the same after adjustment for confounding factors (RR crude: 1.56, CI: 1.07-2.28 and RR adjusted: 1.69, CI: 1.09-2.54). CONCLUSION: Low levels of natural IgM anti-PC could play an important role as risk markers for development of MI. Adjustment for common confounders only marginally affected the RR, suggesting that the addition of IgM anti-PC add independent information to the more traditional risk factors.
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| 27. |
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| 28. |
- Gunnarsson, Rebeqa, et al.
(författare)
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Screening for copy-number alterations and loss of heterozygosity in chronic lymphocytic leukemia-A comparative study of four differently designed, high resolution microarray platforms
- 2008
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 93, s. 0536-0536
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Tidskriftsartikel (refereegranskat)abstract
- Screening for gene copy-number alterations (CNAs) has improved by applying genome-wide microarrays, where SNP arrays also allow analysis of loss of heterozygozity (LOH). We here analyzed 10 chronic lymphocytic leukemia (CLL) samples using four different high-resolution platforms: BAC arrays (32K), oligonucleotide arrays (185K, Agilent), and two SNP arrays (250K, Affymetrix and 317K, Illumina). Cross-platform comparison revealed 29 concordantly detected CNAs, including known recurrent alterations, which confirmed that all platforms are powerful tools when screening for large aberrations. However, detection of 32 additional regions present in 2-3 platforms illustrated a discrepancy in detection of small CNAs, which often involved reported copy-number variations. LOH analysis using dChip revealed concordance of mainly large regions, but showed numerous, small nonoverlapping regions and LOH escaping detection. Evaluation of baseline variation and copy-number ratio response showed the best performance for the Agilent platform and confirmed the robustness of BAC arrays. Accordingly, these platforms demonstrated a higher degree of platform-specific CNAs. The SNP arrays displayed higher technical variation, although this was compensated by high density of elements. Affymetrix detected a higher degree of CNAs compared to Illumina, while the latter showed a lower noise level and higher detection rate in the LOH analysis. Large-scale studies of genomic aberrations are now feasible, but new tools for LOH analysis are requested.
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| 29. |
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| 30. |
- Hanberg, Annika, et al.
(författare)
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Phthalates and their metabolites in human breast milk, blood and urine as measures for monitoring exposure in human risk groups
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- För att undersöka halter av ftalater i svenskar och vilken matris som bäst lämpar sig för hälsorelaterad miljöövervakning har ftalater och ftalatmetaboliter analyserats i en grupp kvinnor som nyligen fött barn. I samband med förlossning på Universitetssjukhuset i Lund tillfrågades förstföderskor om medverkan och 42 kvinnor kom att ingå i studien. När barnet var 2-3 veckor gammalt pumpade mamman ut 50 mL bröstmjölk. Blod- och urinprov togs en vecka senare. Omfattande förändringar av standardmetoder för provtagning av mjölk och blod gjordes för att minimera risken för kontaminering av proverna. För mjölkprovtagningen användes en specialkonstruerad manuell pump av polykarbonat med ftalatfri packning. Blodprov togs med hjälp av endast kanyl och provrör (eftersom propparna i vaccutainrör innehåller ftalater). Proverna förvarades i värmebehandlade glasbehållare och fosforsyra tillsattes för att motverka metabolism av ftalater i mjölk- och blodprover. Analyserna av bröstmjölk visade värden nära eller under detektionsgränsen (LOD) för flertalet ftalater eller deras metaboliter. Även i blod och serum var nivåerna vanligtvis nära eller under LOD. I urin analyserades endast metaboliter och dessa kunde kvantifieras i 53-100 % av proverna. Nivåerna av ftalatmetaboliter i urin hos de svenska kvinnorna var i paritet med nivåerna hos en allmänbefolkning i USA och Tyskland. Några klara korrelationer mellan nivåer i t ex urin och bröstmjölk respektive blod påvisades inte. Resultaten av studien anger att för närvarande är analys av ftalatmetaboliter i urin den mest framkomliga vägen för skattning av ftalatexponering hos människa. Provtagning och analys av mjölk och blod innebar betydligt större svårigheter. Framför allt framstår risken för kontaminering vid provtagning som betydande och en stor del av ftalaterna och dess metaboliter uppvisade låga halter, vid eller under LOD. Dessutom kan ftalater brytas ned i blod och mjölk. I flertalet internationella publicerade studier av ftalatexponering används urinmetabolit-analyser som ett mått på exponering för ftalater. I en nyligen publicerad amerikansk studie av ett 80-tal nyfödda pojkar sågs ett samband mellan kort ano-genitalt avstånd och nivåer av ftalatmetaboliter i urin hos deras mammor under graviditeten. Den amerikanska studien behöver bekräftas, men metaboliterna var desamma som i vår studie och en jämförelse visar att mediannivåerna var lägre för vissa men högre för andra metaboliter. Vår studie indikerar att svenska kvinnor i fertil ålder inte sällan exponeras för ftalater i nivåer som satts i samband med fosterpåverkan.
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