Glacial/interglacial changes in mineral dust and sea-salt records in polar ice cores: sources, transport, and deposition

Sea salt and mineral dust records as represented by Na+ and Ca2+ concentrations, respectively, in Greenland and Antarctic ice cores show pronounced glacial/interglacial variations. For the Last Glacial Maximum (LGM) mineral dust (sea salt) concentrations in Greenland show an increase of a factor of approximately 80 (15) compared to the Holocene and significant shifts by a factor of 15 (5) during Dansgaard Oeschger events. In Antarctica, the dust (sea salt) flux is enhanced by a factor of 15 (3) during the LGM compared to the Holocene and variations by approximately a factor of 8 (1-2) exist in parallel to Antarctic warm events. Primary glacial dust sources are the Asian deserts for Greenland and Patagonia for Antarctica. Ice core evidence and model results show that both changes in source strength as well as atmospheric transport and lifetime contributed to the observed changes in Greenland ice cores. In Antarctica changes in ice core fluxes are in large parts related to source variations both for sea salt and dust, where the formation of sea salt aerosol from sea ice may play a pivotal role. Summarizing our latest estimates on changes in sources, transport and deposition these processes are roughly able to explain the glacial increase in sea salt in both polar regions while they fall short by at least a factor of 4-7 for mineral dust. Future improvements in model resolution and in the formulation of source and transport processes together with new ice core records, e.g. on dust size distributions, will eventually allow to converge models and observations

A Shot at a Healthy Future

In this article, we present an extended case analysis of the unruly reception of the HPV vaccine in Denmark. More specifically, we explore what happens to visions of a healthy future when high levels of social trust in a public vaccination programme are suddenly infused with uncertainty and doubt. Capturing the Danish public in 2013-2015, national news and social media platforms shared dra-matic stories of young women confined to their beds following their HPV vaccinations. The Danish healthcare authorities reacted to this seemingly accelerating problem by setting up HPV clinics to care for the women. Simultaneously, HPV vaccination uptake plunged. Based on long-term ethno-graphic field research, we present the experiences of two main interlocutors, who both find them-selves in difficult situations and having to revise their visions of the future: Sophie, a young woman with suspected HPV vaccine side effects and Martin, a physician working in an HPV clinic. Overall, their accounts shed light on situations emerging during a challenging period in the 2010s in which the Danish healthcare system was adjusting to a new information and media landscape. We show that the promise of a healthy future – sustained by welfare and vaccine technologies – is indeed a communal venture that is vulnerable to suspension and even collapse. When sufferings (such as pain or fatigue) were publicly paired and un-paired with the vaccine, it generated and sustained pervasive uncertainties and painful feelings of being doubted by others – reflecting and highlighting inherent tensions of preventative medicine and the Danish welfare society, including the subtle acts of power and resistance that occur within it

Ammonia transformation in a biotrickling air filter

[Abstract] A simple, tubular biotrickling filter was designed for optimal removal of ammonia and odour in ventilation air from a pig house. The removal and transformation of ammonia was studied in detail by analysis and modelling of chemical gradients through the filter. Good correspondence between measurements and model was obtained by using conventional substrate and inhibition kinetics of ammonium and nitrite oxidizing bacteria. Highest rates of ammonia removal were observed in the central section of the filter. Near the air outlet and water inlet the process was ammonia limited, while high nitrous acid concentrations almost excluded any biological activity near the air inlet and water outlet. Nitrous acid inhibition also stabilized pH at 6.5-7 all through the filter. Being sensitive to both ammonia and nitrous acid the nitrite oxidation process occurred mainly in the filter sections near the air outlet / water inlet, and only 8% of the nitrite was turned into nitrate. Water supply only exceeded evaporation by 20% but modelling indicated that additional watering would have limited effect on filter efficiency. The filter was also robust to varying loading, as a 4-fold increase in ammonia inlet concentration only reduced filter efficiency from 86 to 76%

Proteome analysis of Aspergillus niger: Lactate added in starch-containing medium can increase production of the mycotoxin fumonisin B2 by modifying acetyl-CoA metabolism

<p>Abstract</p> <p>Background</p> <p><it>Aspergillus niger </it>is a filamentous fungus found in the environment, on foods and feeds and is used as host for production of organic acids, enzymes and proteins. The mycotoxin fumonisin B₂was recently found to be produced by <it>A. niger </it>and hence very little is known about production and regulation of this metabolite. Proteome analysis was used with the purpose to reveal how fumonisin B₂production by <it>A. niger </it>is influenced by starch and lactate in the medium.</p> <p>Results</p> <p>Fumonisin B₂production by <it>A. niger </it>was significantly increased when lactate and starch were combined in the medium. Production of a few other <it>A. niger </it>secondary metabolites was affected similarly by lactate and starch (fumonisin B₄, orlandin, desmethylkotanin and pyranonigrin A), while production of others was not (ochratoxin A, ochratoxin alpha, malformin A, malformin C, kotanin, aurasperone B and tensidol B). The proteome of <it>A. niger </it>was clearly different during growth on media containing 3% starch, 3% starch + 3% lactate or 3% lactate. The identity of 59 spots was obtained, mainly those showing higher or lower expression levels on medium with starch and lactate. Many of them were enzymes in primary metabolism and other processes that affect the intracellular level of acetyl-CoA or NADPH. This included enzymes in the pentose phosphate pathway, pyruvate metabolism, the tricarboxylic acid cycle, ammonium assimilation, fatty acid biosynthesis and oxidative stress protection.</p> <p>Conclusions</p> <p>Lactate added in a medium containing nitrate and starch can increase fumonisin B₂production by <it>A. niger </it>as well as production of some other secondary metabolites. Changes in the balance of intracellular metabolites towards a higher level of carbon passing through acetyl-CoA and a high capacity to regenerate NADPH during growth on medium with starch and lactate were found to be the likely cause of this effect. The results lead to the hypothesis that fumonisin production by <it>A. niger </it>is regulated by acetyl-CoA.</p

Reproducibility of the Infinium methylationEPIC BeadChip assay using low DNA amounts

The Infinium MethylationEPIC BeadChip (EPIC) is a reliable method for measuring the DNA methylation of more than 850,000 CpG positions. In clinical and forensic settings, it is critical to be able to work with low DNA amounts without risking reduced reproducibility. We evaluated the EPIC for a range of DNA amounts using two-fold serial dilutions investigated on two different days. While the β-value distributions were generally unaffected by decreasing DNA amounts, the median squared Pearson’s correlation coefficient (R(2)) of between-days β-value comparisons decreased from 0.994 (500 ng DNA) to 0.957 (16 ng DNA). The median standard deviation of the β-values was 0.005 and up to 0.017 (median of medians: 0.014) for β-values around 0.6–0.7. With decreasing amounts of DNA from 500 ng to 16 ng, the percentage of probes with standard deviations ≤ 0.1 decreased from 99.9% to 99.4%. This study showed that high reproducibility results are obtained with DNA amounts in the range 125–500 ng DNA, while DNA amounts equal to 63 ng or below gave less reproducible results

Introduktion: Samtidens usikkerhed

Vores samfund forandrer sig kontinuerligt; teknologier samt demografiske og kulturelle tendenser ændrer vores vilkår og rammer for erkendelse – den måde vi ræsonnerer på, og de muligheder vi har for at træffe valg og handle gennem livet. Menneskers oplevelser og håndtering af usikkerhed og uvished i forbindelse med sygdom og lidelse kalder derfor til hver en tid på empirisk forskning og diskussion. Etymologisk henleder ordet usikkerhed til ’en tilstand af fare’ eller ’at være i en ubehagelig situation’. Ordet er flertydigt og danner meningsfællesskaber med uvished, tilfældighed, uro, ubeslutsomhed, skepsis og ikke mindst tvivl. Denne flertydighed reflekteres formentlig i det paradoksale forhold, at når vi taler om lidelse, sygdom og død, er disse uforudsigelige og dog uundgåelige hændelser i et menneskes liv.

X-ray fluorescence (XRF) fingerprinting of Palaeogene deposits in Denmark

In this study, we test if cost-efficient X-ray fluorescence (XRF) analyses can be used to fingerprint Palaeogene clay and marl deposits in Denmark. A total of 67 samples from key sites in Denmark have been analysed. Our preliminary results indicate that it is possible locally within 10–30 km to distinguish between most of the Palaeogene units, but on a regional scale across Denmark, the units are not unique, and this probably reflects variations in clay mineralogy, grain size and calcareous content. Accordingly, we suggest that a comprehensive reference database is now needed if the full potential of the method is to be utilised, and this will ultimately result in more reliable geological models