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Stockholm, Sweden

Henriques V.M.J.,Royal Swedish Academy Of Sciences | Henriques V.M.J.,Albanova University Center
Astronomy and Astrophysics

Context. The wings of the Caii H and K lines provide excellent photospheric temperature diagnostics. At the Swedish 1-m Solar Telescope (SST), the blue wing of Caii H is scanned with a narrowband interference filter mounted on a rotation stage. This provides up to 0\hbox{$\farcs$}10 spatial resolution filtergrams at high cadence that are concurrent with other diagnostics at longer wavelengths. Aims. The aim is to develop observational techniques that provide photospheric temperature stratification at the highest spatial resolution possible and use them to compare simulations and observations at different heights. Methods. We use filtergrams in the Caii H blue wing that were obtained with a tiltable interference filter at the SST. Synthetic observations are produced from three-dimensional (3D) hydro and magneto-hydrodynamic numerical simulations and degraded to match the observations. The temperature structure obtained from applying the method to the synthetic data is compared with the known structure in the simulated atmospheres and with observations of an active region. Cross-correlation techniques using restored non-simultaneous continuum images are used to reduce high-altitude, small-scale seeing signal introduced from the non-simultaneity of the frames when differentiating data. Results. Temperature extraction using high-resolution filtergrams in the Caii H blue wing works reasonably well when tested with simulated 3D atmospheres. The cross-correlation technique successfully compensates for the problem of small-scale seeing differences and provides a measure of the spurious signal from this source in differentiated data. Synthesized data from the simulated atmospheres (including pores) match well the observations morphologically at different observed heights and in vertical temperature gradients. © 2012 ESO. Source

Lindahl T.,Royal Swedish Academy Of Sciences
Ecological Economics

The role of environmental uncertainty has not been ignored in the common resource literature, but underlying most of this research is an explicit or implicit assumption of symmetric uncertainty. In this paper I relax the assumption of symmetric uncertainty and analyze how knowledge heterogeneity influences coordination problems that can arise in common resource settings. This paper demonstrates that knowledge heterogeneity can work as a coordination device; the more users differ with respect to knowledge, the smaller is the coordination problem as well as the probability of resource breakdown. Less informed users can take advantage of their ignorance at the expense of more informed users. Furthermore, regulation can reduce the coordination problem further, but only by reinforcing the benefit from ignorance. Thus when analyzing and suggesting policies for reducing the inefficiencies associated with common resources where rivalry prevails, one should not only be concerned about the level of environmental uncertainty, but also the distribution, as it matters too. © 2012 Elsevier B.V.. Source

Von Heland J.,University of Stockholm | Folke C.,University of Stockholm | Folke C.,Royal Swedish Academy Of Sciences
Global Environmental Change

We investigate the role of culture in sustaining essential ecosystem services in the arid and erratic climate of an agropastoral landscape in southern Madagascar. Our fieldwork and interviews in Ambovombe subprefecture in Androy addressed land use, agropastoralism, livelihood, institutions and their moral basis. Our analysis points to the interdependence of cultural practices and ecosystem services: sacred forests, crop pollination, subsistence farming, cattle economy and societal transition and purification rituals. We posit a social-ancestral contract that works as a moral attractor structuring and sustaining the agropastoral ecosystem services system. The contract between living and nonliving clan members underpins the cultural practices and rituals that regulate the vulnerable agropastoral system. We conclude that the well-being values of the inhabitants of the south of Madagascar depend upon moralities that lend legitimacy and stability to the management of the social-ecological processes that precondition ecosystem services production. Neither ecosystem nor culture delivers ecosystem services to society. Ecosystem services are generated by an interdependent social-ecological system in which knowledge, practice, and beliefs coevolve: culture is a key factor in their generation and persistence. The study suggests these are significant interdependences to consider in dynamic analyses of ecosystem service production. © 2013 Elsevier Ltd. Source

Kullander S.,Royal Swedish Academy Of Sciences
Ambio

Humankind is currently faced with the huge challenge of securing a sustainable energy supply and biofuels constitute one of the major options. However, the commercially traded edible crops are barely sufficient to meet food demand of the present world population. Certain regions, for example EU-27, do not even have a sufficient indigenous crop production. Of this follows that motor biofuels based on edible crops should be avoided. To replace more than some percent of the fossil motor fuels, non-edible biomass-rest products and wastes-should instead be considered for conversion to biofuels. In this way, about 10% of the current fossil fuels can be replaced. Feeding a world population expected to grow by some 50% during the next 50 years will be a major challenge. For environmental reasons it seems that agricultural land cannot be expanded very much, maybe not at all. The solution to the increasing food demand seems therefore to be using the present crop production more efficiently and increasing output from present agricultural land, maintaining biodiversity and climate stability within reasonable limits. In the future, agriculture will need more energy and more water irrigation. Food production is, however, already very energy demanding, requiring several times more externally provided energy than the energy content of the food itself. A sufficient energy supply will be a key issue for the future farming! © 2010 Royal Swedish Academy of Sciences. Source

Norrby E.,Royal Swedish Academy Of Sciences
Journal of Internal Medicine

Prions represent a group of proteins with a unique capacity to fold into different conformations. One isoform is rich in beta-pleated sheets and can aggregate into amyloid that may be pathogenic. This abnormal form propagates itself by imposing its confirmation on the homologous normal host cell protein. Pathogenic prions have been shown to cause lethal neurodegenerative diseases in humans and animals. These diseases are sometimes infectious and hence referred to as transmissible spongiform encephalopathies. In the present review, the remarkable evolution of the heterodox prion concept is summarized. The origin of this phenomenon is based on information transfer between homologous proteins, without the involvement of nucleic acid-encoded mechanisms. Historically, kuru and Creutzfeldt-Jakob disease (CJD) were the first infectious prion diseases to be identified in man. It was their relationship to scrapie in sheep and experimental rodents that allowed an unravelling of the particular molecular mechanism that underlie the disease process. Transmission between humans has been documented to have occurred in particular contexts, including ritual cannibalism, iatrogenic transmission because of pituitary gland-derived growth hormone or the use in neurosurgical procedures of dura mater from cadavers, and the temporary use of a prion-contaminated protein-rich feed for cows. The latter caused a major outbreak of bovine spongiform encephalopathy, which spread to man by human consumption of contaminated meat, causing approximately 200 cases of variant CJD. All these epidemics now appear to be over because of measures taken to curtail further spread of prions. Recent studies have shown that the mechanism of protein aggregation may apply to a wider range of diseases in and possibly also outside the brain, some of which are relatively common such as Alzheimer's and Parkinson's diseases. Furthermore, it has become apparent that the phenomenon of prion aggregation may have a wider physiological importance, but a full understanding of this remains to be defined. It may involve maintaining neuronal functions and possibly contributing to the establishment of long-term memory. © 2011 The Association for the Publication of the Journal of Internal Medicine. Source

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