Central Jutland Research Articles

IgG subclass antibodies to human and bacterial HSP60 are not associated with disease activity and progression over time in axial spondyloarthritis

IntroductionSpondyloarthritis (SpA), an interrelated group of rheumatic diseases, has been suggested to be triggered by bacterial infections prior to the development of an autoimmune response that causes inflammation of the spinal and peripheral joints. Because human heat shock protein 60 (HSP60), recently renamed HSPD1, and bacterial HSP60 are highly homologous, immunological cross-reactivity has been proposed as a mechanism of disease initiation. However, previous investigations of the humoral immune response to HSP60 in SpA patients have lacked determination of immunoglobulin G (IgG) subclasses and patient follow-up. In this study, we have focused on these parameters in a cohort of axial SpA patients with a well-established set of clinical characteristics, including MRI changes and human leukocyte antigen B27.MethodsIgG subclass antibodies (IgG1, IgG2, IgG3 and IgG4) against recombinant HSP60 of three reactive arthritis-related bacteria; human HSP60; and the microorganisms Chlamydia trachomatis and C. pneumoniae were determined by ELISA. Serum samples collected from 2004 to 2006 and in 2010 and 2011 from 39 axial SpA patients were analyzed and compared with samples from 39 healthy controls. The Mann-Whitney U test and Wilcoxon matched pairs test were used to compare the antibody levels in different and paired groups, respectively. P < 0.01 was considered significant. The Spearman nonparametric correlation was used to determine correlation between antibody levels and between antibody levels and the disease parameters.ResultsElevated levels of IgG1 and IgG3 to human HSP60 and IgG1 to HSP60 of Salmonella enterica Enteritidis were observed in SpA patients compared with healthy controls at both time points. The antibody levels were almost constant over time for IgG1, whereas high levels of IgG3 to human HSP60 tended to decrease over time. The antibody response to human HSP60 was predominantly of the IgG3 subclass, and patients with high levels of IgG3 to this antigen had low levels of IgG1, indicating an inverse association. Different IgG subclasses were produced against bacterial and human HSP60 in the same serum sample, IgG1 and IgG3, respectively, indicating that there was no cross-reaction.ConclusionsA significant association was observed between axial SpA and the presence of IgG1/IgG3 antibodies to human HSP60 and of IgG1 to S. enterica Enteritidis and C. trachomatis. Generation of antibodies to human HSP60 was independent of the presence of antibodies to bacterial HSP60. No association was observed between clinical and MRI changes with antibodies over time. Altogether, such antibodies do not reflect the disease activity in these patients.This study has been approved by the Regional Research Ethics Committee of Central Jutland, Denmark. Trial registration numbers: 20050046 and 20100083

Spatial distribution of soils determines export of nitrogen and dissolved organic carbon from an intensively managed agricultural landscape

Abstract. The surrounding landscape of a stream has crucial impacts on the aquatic environment. This study pictures the hydro-biogeochemical situation of the Tyrebækken creek catchment in central Jutland, Denmark. The intensively managed agricultural landscape is dominated by rotational croplands. The small catchment mainly consist of sandy soil types besides organic soils along the streams. The aim of the study was to characterise the relative influence of soil type and land use on stream water quality. Nine snapshot sampling campaigns were undertaken during the growing season of 2009. Total dissolved nitrogen (TDN), nitrate (NO3−), ammonium nitrogen and dissolved organic carbon (DOC) concentrations were measured, and dissolved organic nitrogen (DON) was calculated for each grabbed sample. Electrical conductivity, pH and flow velocity were measured during sampling. Statistical analyses showed significant differences between the northern, southern and converged stream parts, especially for NO3− concentrations with average values between 1.4 mg N l−1 and 9.6 mg N l−1. Furthermore, throughout the sampling period DON concentrations increased to 2.8 mg N l−1 in the northern stream contributing up to 81% to TDN. Multiple-linear regression analyses performed between chemical data and landscape characteristics showed a significant negative influence of organic soils on instream N concentrations and corresponding losses in spite of their overall minor share of the agricultural land (12.9%). On the other hand, organic soil frequency was positively correlated to the corresponding DOC concentrations. Croplands also had a significant influence but with weaker correlations. For our case study we conclude that the fractions of coarse textured and organic soils have a major influence on N and DOC export in this intensively used landscape. Meanwhile, the contribution of DON to the total N losses was substantial.

Validation of the 12 Item Short form Health Survey in a Sample from Region Central Jutland

In 2010 the Danish regions started a new program of public health surveillance in collaboration with the national and local health authorities using the short form health survey (SF-12) for measuring and reporting on health related quality of life among the Danish adult population. The instrument has not, however, been validated in a Danish setting. The aim of this study was to assess the reliability and validity of the physical component summary (PCS) and the mental component summary (MCS) score of the 12-item short form health survey (SF-12) in a sample from Central Denmark Region. A total of 26,397 persons above the age of 25 were included in the analyses. Reliability was assessed by Cronbach’s α. The validity was assessed using known-groups comparisons and convergent validity. The factor structure was investigated through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The Cronbach’s α showed high reliability with a score of 0.90 and 0.85 for PCS and MCS respectively. The SF-12 discriminated well with respect to gender, age, educational status and long term illness. Individual items correlated higher with own hypothesized scales than with other scales and summary measures corroborating the convergent validity. The EFA gave a two-factor structure. Irrespective of the chosen rotation method (varimax and oblimin) the items related to PCS loaded on one factor and the items related to MCS loaded on another factor. The factor structure was validated with acceptable model-fit values in CFA. The SF-12 instrument is a reliable and valid measure of health related quality of life among the population of Central Denmark Region.

Middle Eocene to earliest Oligocene development in the eastern North Sea Basin: Biostratigraphy, magnetostratigraphy and palaeoenvironment of the Kysing-4 borehole, Denmark

The cored 154.5m deep Kysing-4 borehole in central Jutland is unique for high northern latitudes because it comprises an almost complete Middle Eocene to lowermost Oligocene succession mostly in a highly calcareous facies with abundant well preserved microfossils and from an upper bathyal environment. It has therefore been possible to carry out biostratigraphical analyses of calcareous nannofossils, benthic and planktonic foraminifera as well as dinoflagellate cysts. In order to correlate the section to the geomagnetic polarity time scale a detailed palaeomagnetic analysis has been performed. The magnetobiostratigraphic calibration allowed a well constrained identification of nearly all magnetochrons between Chron C21n and Chron C13n. The Eocene deposits consist mostly of calcareous ooze (Søvind Marl Formation with three new members formally defined), whereas the Oligocene Viborg Formation consists of moderately calcareous mud. Overall, the lithology of the deposits is in agreement with previous interpretations of a British provenance for the Eocene deposits and a Scandinavian provenance for the Oligocene deposits. Cyclic shifts in the clay/carbonate content during the Middle Eocene (chrons C19–C17) are attributed to orbitally controlled climate shifts. Obliquity seems to have been the dominating factor, but intervals dominated by precession end eccentricity signals also occur. A 10m thick hitherto unknown black mud (Moesgaard Member) of Scandinavian provenance and deposited very rapidly during the late Eocene Chron C16n.1n is interpreted as a precursor event to the Oligocene mode of sedimentation. Both the Moesgaard Member and the Lower Oligocene Viborg Formation are associated with sea-level falls.

Bio- and magnetostratigraphy of Rupelian–mid Chattian deposits from the Danish land area

The age of the lithostratigraphic units in the Oligocene succession of Denmark is not well known. In order to remedy this situation, an integrated bio-magnetostratigraphical study of the Rupelian–mid Chattian deposits was carried out on six key sections situated in central Jutland. The studied sections include all previously known lithostratigraphical units (i.e., the Grundfør and Viborg Clay Members of the Viborg Formation, Linde Clay, Hvorslev Clay, Branden Clay) and a new, informal Unit X.The biostratigraphical part of the paper critically discusses the differences in ranges of some dinoflagellate cysts in relation to the two most commonly applied dinocyst zonations, the D- and NSO-zonation. The local calcareous nannofossil zonation of the upper NP23–lower NP25 interval in the studied sections is correlated to the standard NP zonation via the Contessa Barbetti Road section in central Italy. The correlation shows that an interval of the range of the dinoflagellate cyst Svalbardella recognized within the lower Chattian Asterigerina guerichi guerichi Zone in Denmark and Belgium is coeval with the global Oi2b cooling event.The identified magnetic polarity intervals have been correlated with the global polarity time scale on the basis of the biostratigraphy. The Viborg Formation is thus referred to Chron C13n and the lowermost part of C12r; the Linde Clay is referred to lower Chron C12r; and the Hvorslev Clay is referred to Chron C11n, C10 and C9r, or only the C11n.1n–C10r interval. The Branden Clay is referred to Chron C9r, C9n and C8r. Unit X is referred to Chron C8n.

Winter wheat yield response to climate variability in Denmark

SUMMARYData on grain yield from field trials on winter wheat under conventional farming, harvested between 1992 and 2008, were combined with daily weather data available for 44 grids covering Denmark. Nine agroclimatic indices were calculated and used for describing the relation between weather data and grain yield. These indices were calculated as average temperature, radiation and precipitation during winter (1 October–31 March), spring (1 April–15 June) and summer (16 June–31 July), and they were included as linear and quadratic covariates in a mixed regression model. The model also included an effect of year to describe the change in yield caused by unrecorded variables such as management changes. The final model included all effects that were significant for at least one of the two soil types (sandy and loamy soils). Seven of the nine agroclimatic indices were included in the final model that was used to predict the wheat grain yield under five climate scenarios (a baseline for 1985 and two climate change projections for 2020 and 2040) for two soil types and two locations in Denmark.The agroclimatic index for summer temperature showed the strongest effect causing lower yields with increasing temperature, whereas yield increased with increasing radiation during summer and spring. Winter precipitation and spring temperature did not affect grain yield significantly. Grain yield responded non-linearly to mean winter temperature with the highest yield at 4·4°C and lower yields both below and above this inflection point.The application of the model predicted that the average yield would decrease under projected climate change. The average decrease varied between 0·1 and 0·8 t/ha (comparable to a relative reduction of 1·6–12.3%) depending on the climate projection, location and soil type. On average, the grain yield decreased by about 0·25 t/ha (c. 3.6%) from 1985 to 2020 and by about 0·55 t/ha (c. 8·0%) from 1985 to 2040. The predicted yield decrease depended on climate projection and was larger for wheat grown in West Zealand than in Central Jutland and in most cases also larger for loamy soils than for sandy soils.The inter-annual variation in grain yield varied greatly between climate projections. The coefficient of variation (CV) varied between 0·16 and 0·46 and was smallest for wheat grown on loamy soils in Central Jutland in the baseline climate and largest for winter wheat grown under one of the 2040 climate projections. The increase in CV is not so much an effect of increased climatic variability under the climate change projections, but more an effect of increased winter temperature, where more extreme winter temperatures (lower or higher than the inflection point at 4·4°C) increased the effect of winter temperatures.

A Comprehensive Investigation on Iron Cycling in a Freshwater Seep Including Microscopy, Cultivation and Molecular Community Analysis

Iron reduction and oxidation, as well as the microbial community involved in these processes, were investigated in a small pond that is continuously fed by slightly acidic, hypoxic, iron rich ground water. The seep area is located in a beech forest in central Jutland (Denmark), and beech litter is the dominant source of organic matter, carbon and energy for the microbial community. The pond is 30 to 50 cm deep with a water column depth ranging from 15 to 20 cm. Oxygen could only be detected down to 7 cm depth of the water column. Fe(II) concentrations increased with depth from about 30 μM close to the surface to ca. 100 μM at the bottom. The presence of Gallionella- and Sideroxidans-related strains was supported by clone library data, while Leptothrix-related 16S rDNA clones were not found. Samples amended with leaves, acetate, lactate and ethanol all showed stimulated iron reduction at the in situ temperature (about 10°C). In particular, dried beech leaves stimulated iron reduction without a lag phase while acetate was only degraded after a 22 day lag period at the in situ pH. The long lag phase is most probably due to the low pH that is responsible for high acetic acid concentrations (0.8–1.2 mM) at the start of the incubation. Light microscopy observations confirm the clone library data that Gallionella spp and other iron oxidizer related 16S rDNA sequences were relatively common. In addition, 16S rDNA sequences relatively similar to sequences of members of the iron reducer family Geobacteraceae were found. A clone library constructed with a primer set targeting specifically Geobacter-related strains revealed that strains most closely related to Geobacter thiogenes were predominant (19 out of 20 clones). By a combination of microscopy, cultivation and molecular investigations we have been able to provide several lines of evidence for a tight coupling of biological iron reduction and oxidation in this iron-rich fresh water seep.

Rosetfiblens »anatomi«

Rosetfiblens »anatomi«

Kogegruber – i klynger eller på rad og række

Kogegruber – i klynger eller på rad og række

MRS applicability for a study of glacial sedimentary aquifers in Central Jutland, Denmark

Intensive geophysical measurements are currently being carried out in Denmark to comply with the Danish Government's environmental plans of dense hydrogeological mapping to ensure high quality non-treated drinking water supply based solely on groundwater. A MRS-TDEM combined geophysical survey was conducted to measure the applicability and the contribution of MRS to running drilling programs. Despite complicated electromagnetic noise conditions, the MRS method proved to be applicable in the Danish context. An example of the practical application of MRS combined with TDEM in two selected areas of the former County of Vejle in Denmark, demonstrates the efficiency of the technique. The MRS results clearly suggest optimal locations for water supply boreholes within subsurface structures with homogeneous resistivity conditions mapped by TDEM. These results reveal the interest of using MRS as a new geophysical tool for the Danish water supply policy, which can provide a foundation for optimising drilling site locations within areas with resistivities in the aquifer range. However, more MRS soundings need to be carried out in order to improve MRS calibration in the Danish context, which will allow quantitative MRS characterization of aquifers.

Reproductive isolation, evolutionary distinctiveness and setting conservation priorities: The case of European lake whitefish and the endangered North Sea houting (Coregonus spp.)

BackgroundAdaptive radiation within fishes of the Coregonus lavaretus complex has created numerous morphs, posing significant challenges for taxonomy and conservation priorities. The highly endangered North Sea houting (C. oxyrhynchus; abbreviated NSH) has been considered a separate species from European lake whitefish (C. lavaretus; abbreviated ELW) due to morphological divergence and adaptation to oceanic salinities. However, its evolutionary and taxonomic status is controversial. We analysed microsatellite DNA polymorphism in nine populations from the Jutland Peninsula and the Baltic Sea, representing NSH (three populations, two of which are reintroduced) and ELW (six populations). The objectives were to: 1) analyse postglacial recolonization of whitefish in the region; 2) assess the evolutionary distinctiveness of NSH, and 3) apply several approaches for defining conservation units towards setting conservation priorities for NSH.ResultsBayesian cluster analyses of genetic differentiation identified four major groups, corresponding to NSH and three groups of ELW (Western Jutland, Central Jutland, Baltic Sea). Estimates of historical migration rates indicated recolonization in a north-eastern direction, suggesting that all except the Baltic Sea population predominantly represent postglacial recolonization via the ancient Elbe River. Contemporary gene flow has not occurred between NSH and ELW, with a divergence time within the last 4,000 years suggested from coalescence methods. NSH showed interbreeding with ELW when brought into contact by stocking. Thus, reproductive isolation of NSH was not absolute, although possible interbreeding beyond the F1 level could not be resolved.ConclusionFishes of the C. lavaretus complex in the Jutland Peninsula originate from the same recolonization event. NSH has evolved recently and its species status may be questioned due to incomplete reproductive isolation from ELW, but it was shown to merit consideration as an independent conservation unit. Yet, application of several approaches for defining conservation units generated mixed outcomes regarding its conservation priority. Within the total species complex, it remains one among many recently evolved unique forms. Its uniqueness and high conservation priority is more evident at a local geographical scale, where conservation efforts will also benefit populations of a number of other endangered species.

Stenkast

Stenkast

Pediastrum algae from the classic late glacial Bølling Sø site, Denmark: Response of aquatic biota to climate change

The late glacial and the early Holocene sediments of the classic site Bølling Sø in Denmark are being reinvestigated by multi-proxy analyses. We present here the record of Pediastrum species and discuss the climate-mediated changes in the aquatic ecosystem, as reflected by aquatic proxies (e.g. aquatic plants and mosses, cladocerans, ostracods, bryozoan statoblasts), as well as a number of other proxies (organic content, biogenic silica, carbonates, terrestrial plant macrofossils). Climate had warmed to such an extent at c. 12,500 14C yrs BP that aquatic life could begin. Productivity was low and only very scarce indication of a warmer interval predating the Allerød chronozone was found. At the beginning of the Allerød chronozone climate ameliorated and productivity clearly increased. The cool climate of the Younger Dryas chronozone (YD) was more clearly reflected in the terrestrial ecosystem than in the aquatic ecosystem, where productivity appeared to remain rather high. The lake was very shallow and non-stratified during the YD, indicating low effective moisture. Probably it warmed throughout early in the open-water season and in that way enabled higher productivity, even if summer temperatures were rather low. It is also possible that the difference in July temperatures between the late part of the Allerød chronozone and the YD was not large in central Jutland. The amelioration of climate at the beginning of the Holocene is clearly reflected in all proxies. There is also evidence that the lake level rose. The lake probably remained alkaline during all of its history but some evidence suggests that pH was somewhat lowered during the YD chronozone. Pediastrum species appear to be relatively good indicators of environmental conditions; similarly, the concentrations may reflect productivity variations during changing climatic conditions.

Resenlund og Brøndumgård bronzedepoter – Kult og samfund i yngre bronzealder

Resenlund og Brøndumgård bronzedepoter – Kult og samfund i yngre bronzealder

A public summer school on astronomy in Denmark: experience from the course in 2002, 2003 and 2004

Abstract. During the summers of 2002, 2003 and 2004 a one-week public course on Astronomy took place at Silkeborg Folk High School in central Jutland, Denmark. The aim of the course was to offer a possibility for students to meet research scientists and discuss central scientific questions and their answers. Researchers from the Department of Physics and Astronomy at Aarhus University in Denmark took an active part in running this summer school and the course could also be seen as a part of the Department's general public outreach activities. The main aim of those activities is to: (1) show why research is important, (2) give students and children the possibility to meet people that do research, and (3) present authentic role models.

Inferences of selection and migration in the Danish house mouse hybrid zone

We analysed the patterns of allele frequency change for ten diagnostic autosomal allozyme loci in the hybrid zone between the house mouse subspecies Mus musculus domesticus and M. m. musculus in central Jutland. After determining the general orientation of the clines of allele frequencies, we analysed the dine shapes along the direction of maximum gradient. Eight of the ten clines are best described by steep central steps with coincident positions and an average width of 8.9 km (support limits 7.6-12.4) flanked by tails of introgression, indicating the existence of a barrier to gene flow and only weak selection on the loci studied. We derived estimates of migration from linkage disequilibrium in the centre of the zone, and by applying isolation by distance methods to microsatellite data from some of these populations. These give concordant estimates of σ = 0.5-0.8 km generation -1/2 . The barrier to gene flow is of the order of 20 km (support limits 14-28), and could be explained by selection of a few per cent at 43-120 under-dominant loci that reduces the mean fitness in the central populations to 0.45. Some of the clines appear symmetrical, whereas others are strongly asymmetrical, and two loci appear to have escaped the central barrier to gene flow, reflecting the differential action of selection on different parts of the genome. Asymmetry is always in the direction of more introgression into musculus, indicating either a general progression of domesticus into the musculus territory, possibly mediated by differential behaviour, or past movement of the hybrid zone in the opposite direction, impeded by potential geographical barriers to migration in domesticus territory.

Rejecting the mean: Estimating the response of fen plant species to environmental factors by non‐linear quantile regression

AbstractQuestion:Is quantile regression an appropriate statistical approach to estimate the response of fen species to single environmental factors?Background:Data sets in vegetation field studies are often characterized by a large number of zeros and they are generally incomplete in respect to the factors which possibly influence plant species distribution. Thus, it is problematic to relate plant species abundance to single environmental factors by the ordinary least squares regression technique of the conditional mean.Location:Riparian herbaceous fen in central Jutland (Denmark).Methods:Semi‐parametric quantile regression was used to estimate the response of 18 plant species to six environmental factors, 95% regression quantiles were chosen to reduce the impact of multiple unmeasured factors on the regression analyses. Results of 95% quantile regression and ordinary least squares regression were compared.Results:The standard regression of the conditional mean underestimated the rates of change of species cover due to the selected factor in comparison to 95% regression quantiles. The fitted response curves indicated a general broad tolerance of the studied fen species to different flooding durations but a narrower range concerning groundwater amplitude. The cover of all species was related to soil exchangeable phosphate and base‐richness. A relationship between soil exchangeable potassium and species cover was only found for 11 species.Conclusion:Considering the characteristics of data sets in vegetation science, non‐linear quantile regression is a useful method for gradient analyses.

Rejecting the mean: Estimating the response of fen plant species to environmental factors by non-linear quantile regression

Abstract Question: Is quantile regression an appropriate statistical approach to estimate the response of fen species to single environmental factors? Background: Data sets in vegetation field studies are often characterized by a large number of zeros and they are generally incomplete in respect to the factors which possibly influence plant species distribution. Thus, it is problematic to relate plant species abundance to single environmental factors by the ordinary least squares regression technique of the conditional mean. Location: Riparian herbaceous fen in central Jutland (Denmark). Methods: Semi-parametric quantile regression was used to estimate the response of 18 plant species to six environmental factors, 95% regression quantiles were chosen to reduce the impact of multiple unmeasured factors on the regression analyses. Results of 95% quantile regression and ordinary least squares regression were compared. Results: The standard regression of the conditional mean underestimated the rates of change...

En højgruppe ved Kvindvad, Vestjylland

En højgruppe ved Kvindvad, Vestjylland

Landscape changes in agrarian landscapes in the 1990s: the interaction between farmers and the farmed landscape. A case study from Jutland, Denmark

Recent landscape changes in a farmed landscape are analysed and related to farm and farmer characteristics. It is assumed that farm and farmer characteristics serve as mediators of large scale or macro driving forces of change—in the present case, a changing farming context including demands for a more environmentally friendly farming practise and a reduced output. The results are based on multivariate analyses of data collected from structured interviews of 160 farmers in a case study area, in central Jutland, measuring 5000 ha. The analysis shows that farmers are highly involved in landscape changes. The investigated landscape changes include creation and removal of landscape elements as well as certain management changes. The most common activity was creation of elements: hedgerows, small woodlands and conversion of rotational arable land to permanent grassland, whereas removal of elements, mainly hedgerows and semi-natural grasslands, were seen less frequently. Management changes like abandonment of permanent grassland were widespread. The results indicate a general extensification of the land use and the authors interpret the results partly as an indication of a change from productivism to a more multifunctional agricultural regime. The observed landscape changes at the farm level show a low, but structured relationship with the current farm and farmer characteristics, meaning that landscape changes were undertaken by various farmers and on various farms. On a general level, however, the age of the farmer and the duration of farm ownership seem to have a major influence on the landscape changes.