En rejse til Nørresundby og videre ud

Årbogen har flere gange bragt beskrivelser af rejser ombord på sejlskibe. Forfatteren, der tidligere var redaktør ved Ritzaus Bureau, giver her en skildring af sin rejse til det fjerne Østen som messedreng på et af Østasiatisk Kompagnis første motorskibe i 1923-24. Foruden om de rutinemæssige og de usædvanlige oplevelser undervejs fortæller han om dagliglivet ombord, om miljøet, om personerne og om den mangel på kontakt med den store verden, som langfarerne endnu dengang havde

Microarray-based method for detection of unknown genetic modifications

<p>Abstract</p> <p>Background</p> <p>Due to the increased use of genetic modifications in crop improvement, there is a need to develop effective methods for the detection of both known and unknown transgene constructs in plants. We have developed a strategy for detection and characterization of unknown genetic modifications and we present a proof of concept for this method using <it>Arabidopsis thaliana </it>and <it>Oryza sativa </it>(rice). The approach relies on direct hybridization of total genomic DNA to high density microarrays designed to have probes tiled throughout a set of reference sequences.</p> <p>Results</p> <p>We show that by using arrays with 25 basepair probes covering both strands of a set of 235 vectors (2 million basepairs) we can detect transgene sequences in transformed lines of <it>A. thaliana </it>and rice without prior knowledge about the transformation vectors or the T-DNA constructs used to generate the studied plants.</p> <p>Conclusion</p> <p>The approach should allow the user to detect the presence of transgene sequences and get sufficient information for further characterization of unknown genetic constructs in plants. The only requirements are access to a small amount of pure transgene plant material, that the genetic construct in question is above a certain size (here ≥ 140 basepairs) and that parts of the construct shows some degree of sequence similarity with published genetic elements.</p

Liver cirrhosis, other liver diseases, and risk of hospitalisation for intracerebral haemorrhage: A Danish population-based case-control study

<p>Abstract</p> <p>Background</p> <p>Liver diseases are suspected risk factors for intracerebral haemorrhage (ICH). We conducted a population-based case-control study to examine risk of ICH among hospitalised patients with liver cirrhosis and other liver diseases.</p> <p>Methods</p> <p>We used data from the hospital discharge registries (1991–2003) and the Civil Registration System in Denmark, to identify 3,522 cases of first-time hospitalisation for ICH and 35,173 sex- and age-matched population controls. Among cases and controls we identified patients with a discharge diagnosis of liver cirrhosis or other liver diseases before the date of ICH. We computed odds ratios for ICH by conditional logistic regressions, adjusting for a number of confounding factors.</p> <p>Results</p> <p>There was an increased risk of ICH for patients with alcoholic liver cirrhosis (adjusted OR = 4.8, 95% CI: 2.7–8.3), non-alcoholic liver cirrhosis (adjusted OR = 7.7, 95% CI: 2.0–28.9) and non-cirrhotic alcoholic liver disease (adjusted OR = 5.4, 95%CI:3.1–9.5) but not for patients with non-cirrhotic non-alcoholic liver diseases (adjusted OR = 0.9, 95%CI:0.5–1.6). The highest risk was found among women with liver cirrhosis (OR = 8.9, 95%CI:2.9–26.7) and for patients younger than 70 years (OR = 6.1, 95%CI:3.4–10.9). There were no sex- or age-related differences in the association between other liver diseases (alcoholic or non-alcoholic) and hospitalisation with ICH.</p> <p>Conclusion</p> <p>Patients with liver cirrhosis and non-cirrhotic alcoholic liver disease have a clearly increased risk for ICH.</p

Experimental Incubations Elicit Profound Changes in Community Transcription in OMZ Bacterioplankton

Sequencing of microbial community RNA (metatranscriptome) is a useful approach for assessing gene expression in microorganisms from the natural environment. This method has revealed transcriptional patterns in situ, but can also be used to detect transcriptional cascades in microcosms following experimental perturbation. Unambiguously identifying differential transcription between control and experimental treatments requires constraining effects that are simply due to sampling and bottle enclosure. These effects remain largely uncharacterized for “challenging” microbial samples, such as those from anoxic regions that require special handling to maintain in situ conditions. Here, we demonstrate substantial changes in microbial transcription induced by sample collection and incubation in experimental bioreactors. Microbial communities were sampled from the water column of a marine oxygen minimum zone by a pump system that introduced minimal oxygen contamination and subsequently incubated in bioreactors under near in situ oxygen and temperature conditions. Relative to the source water, experimental samples became dominated by transcripts suggestive of cell stress, including chaperone, protease, and RNA degradation genes from diverse taxa, with strong representation from SAR11-like alphaproteobacteria. In tandem, transcripts matching facultative anaerobic gammaproteobacteria of the Alteromonadales (e.g., Colwellia) increased 4–13 fold up to 43% of coding transcripts, and encoded a diverse gene set suggestive of protein synthesis and cell growth. We interpret these patterns as taxon-specific responses to combined environmental changes in the bioreactors, including shifts in substrate or oxygen availability, and minor temperature and pressure changes during sampling with the pump system. Whether such changes confound analysis of transcriptional patterns may vary based on the design of the experiment, the taxonomic composition of the source community, and on the metabolic linkages between community members. These data highlight the impressive capacity for transcriptional changes within complex microbial communities, underscoring the need for caution when inferring in situ metabolism based on transcript abundances in experimental incubations

Effects of Specific Inhibitors on Anammox and Denitrification in Marine Sediments▿

The effects of three metabolic inhibitors (acetylene, methanol, and allylthiourea [ATU]) on the pathways of N2 production were investigated by using short anoxic incubations of marine sediment with a 15N isotope technique. Acetylene inhibited ammonium oxidation through the anammox pathway as the oxidation rate decreased exponentially with increasing acetylene concentration; the rate decay constant was 0.10 ± 0.02 μM−1, and there was 95% inhibition at ∼30 μM. Nitrous oxide reduction, the final step of denitrification, was not sensitive to acetylene concentrations below 10 μM. However, nitrous oxide reduction was inhibited by higher concentrations, and the sensitivity was approximately one-half the sensitivity of anammox (decay constant, 0.049 ± 0.004 μM−1; 95% inhibition at ∼70 μM). Methanol specifically inhibited anammox with a decay constant of 0.79 ± 0.12 mM−1, and thus 3 to 4 mM methanol was required for nearly complete inhibition. This level of methanol stimulated denitrification by ∼50%. ATU did not have marked effects on the rates of anammox and denitrification. The profile of inhibitor effects on anammox agreed with the results of studies of the process in wastewater bioreactors, which confirmed the similarity between the anammox bacteria in bioreactors and natural environments. Acetylene and methanol can be used to separate anammox and denitrification, but the effects of these compounds on nitrification limits their use in studies of these processes in systems where nitrification is an important source of nitrate. The observed differential effects of acetylene and methanol on anammox and denitrification support our current understanding of the two main pathways of N2 production in marine sediments and the use of 15N isotope methods for their quantification