| 1. |
- Bursa, M., et al.
(författare)
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The timescale of encircling light
- 2007
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Ingår i: Silesian University in Opava. ; , s. 21-25
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Konferensbidrag (refereegranskat)abstract
- We show that in some astronomical sources containing black holes, the signature of the circular photon orbit may be detected by searching for the shortest timescale in the variability data. A positive detection would provide the direct empirical support for Einstein's general relativity in its super-strong field limit, relevant to black holes.
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| 2. |
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| 3. |
- Dass, Pawlok, et al.
(författare)
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Grasslands may be more reliable carbon sinks than forests in California
- 2018
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 13:7
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Tidskriftsartikel (refereegranskat)abstract
- Although natural terrestrial ecosystems have sequestered ∼25% of anthropogenic CO2 emissions, the long-term sustainability of this key ecosystem service is under question. Forests have traditionally been viewed as robust carbon (C) sinks; however, extreme heat-waves, drought and wildfire have increased tree mortality, particularly in widespread semi-arid regions, which account for ∼41% of Earth's land surface. Using a set of modeling experiments, we show that California grasslands are a more resilient C sink than forests in response to 21st century changes in climate, with implications for designing climate-smart Cap and Trade offset policies. The resilience of grasslands to rising temperatures, drought and fire, coupled with the preferential banking of C to belowground sinks, helps to preserve sequestered terrestrial C and prevent it from re-entering the atmosphere. In contrast, California forests appear unable to cope with unmitigated global changes in the climate, switching from substantial C sinks to C sources by at least the mid-21st century. These results highlight the inherent risk of relying on forest C offsets in the absence of management interventions to avoid substantial fire-driven C emissions. On the other hand, since grassland environments, including tree-sparse rangelands, appear more capable of maintaining C sinks in 21st century, such ecosystems should be considered as an alternative C offset to climate-vulnerable forests. The further development of climate-smart approaches in California's carbon marketplace could serve as an example to offset programs around the world, particularly those expanding into widespread arid and semi-arid regions.
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| 4. |
- Ekholm, Hanna Matschke, et al.
(författare)
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Social hållbarhet - en introduktion kring begreppet och dess relevans för energisektorns aktörer
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Social hållbarhet är en lika självklar del av hållbar utveckling som den ekologiska och ekonomiska hållbarheten. De flesta företag arbetar aktivt med social hållbarhet i sina or-ganisationer via bland annat personalvård och erbjudanden om kultur- och friskvårdsak-tiviteter. Idag är det även många företag som arbetar med externa aktiviteter avseende att stärka och bevara social hållbarhet i samhället där man verkar. Men vad innebär detta i praktiken, och vad mer specifikt handlar ett aktivt externt arbete med social hållbarhet om för energisektorns aktörer.
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| 5. |
- Ekholm, I Elisabeth, et al.
(författare)
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Stratum corneum tryptic enzyme in normal epidermis : a missing link in the desquamation process?
- 2000
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Ingår i: Journal of Investigative Dermatology. - : Nature Publishing Group. - 0022-202X .- 1523-1747. ; 114:1, s. 56-63
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Tidskriftsartikel (refereegranskat)abstract
- Stratum corneum chymotryptic enzyme may be important in desquamation. It has also been suggested that other proteases, especially stratum corneum tryptic enzyme, may be involved. Stratum corneum tryptic enzyme has been purified and its cDNA has been cloned. Results from expression analyses indicate that stratum corneum tryptic enzyme is as skin specific as stratum corneum chymotryptic enzyme. In this work we have produced and characterized antibodies specific for stratum corneum tryptic enzyme. We have also by means of biochemical, immunochemical, and immunohistochemical methods performed studies on stratum corneum tryptic enzyme in normal human epidermis. Antibodies against bacterial recombinant stratum corneum tryptic enzyme were produced and purified by affinity chromatography. Two types of antibodies were obtained: one reacting only with pro-stratum corneum tryptic enzyme and one specific for the catalytically active part of stratum corneum tryptic enzyme. Immunohistochemistry with the antibodies reacting with pro-stratum corneum tryptic enzyme showed a staining pattern similar to stratum corneum chymotryptic enzyme-specific antibodies, i.e., the expression was confined to cornifying epithelia with a need of desquamation-like processes. Extracts of tape strips with superficial human stratum corneum were found to contain precursors as well as active forms of stratum corneum tryptic enzyme and stratum corneum chymotryptic enzyme. The enzymes had maximal activity at pH 8, but both had considerable activity also at pH 5.5. The results were compatible for a role of stratum corneum tryptic enzyme in desquamation. Stratum corneum tryptic enzyme may act in concert with stratum corneum chymotryptic enzyme and/or function as a stratum corneum chymotryptic enzyme-activating enzyme. The presence in normal superficial stratum corneum of precursors as well as of active forms of stratum corneum chymotryptic enzyme and stratum corneum tryptic enzyme, and the activity of both enzymes over a broad range of pH-values, suggest some possible ways by which the desquamation may be regulated.
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| 6. |
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| 7. |
- Klintman, Mikael, et al.
(författare)
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Academia and society in collaborative knowledge production towards urban sustainability : several schemes—three common crossroads
- 2022
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Ingår i: Environment, Development and Sustainability. - : Springer Science and Business Media LLC. - 1387-585X .- 1573-2975.
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Tidskriftsartikel (refereegranskat)abstract
- Arrangements for collaboration in knowledge production across academia, government, non-governmental organisations, and corporations have several names, such as citizen-science, community-based participatory research, engaged research and hybrid forums. The multiplicity of schemes does not lie only in the high number of names for various versions of collaborative knowledge production. Different scholars also use concepts in multiple ways, depending on their individual choices, mother disciplines, and the problem area in which collaboration occurs. At the same time, there is a lack of analytical tools that address the full range of collaborative research schemes and provide a systematic set of questions to learn about the schemes, challenges, and opportunities. Based on our review of academic journal articles highlighting collaborative research schemes, this paper aims to analyse three parameters which it is fair to say that virtually all arrangements of collaborative knowledge production ought to consider when making decisions, parameters that are often partially missed or misunderstood: (A) epistemic-procedural, (B) exclusive-inclusive and (C) aggregative-integrative. By examining the three parameters, their political theory origins, and how they connect to and challenge existing schemes of knowledge collaboration, we provide analytical tools that could facilitate processes of developing and scrutinising arrangements of collaborative research.
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| 8. |
- Pedersen, NL, et al.
(författare)
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Neuroimaging findings in twins discordant for Alzheimer's disease
- 1999
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 10:1, s. 51-58
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Tidskriftsartikel (refereegranskat)abstract
- Data from computed tomography (CT) scans of 12 twin pairs in which one partner had Azheimer’s disease (AD) and the other partner is cognitively intact were analyzed to study structural brain features associated with AD while controlling for familial factors. Visual ratings and analysis of quantified areas and volumes indicated that AD twins showed more dilation of temporal horns, lateral ventricles and third ventricle, and more atrophy of temporal lobes, particularly in the anterior temporal/perisylvian area, than their healthy cotwins. Demented twins did not have smaller intracranial areas or overall brain volumes than their intact partners. The apolipoprotein σ-4 allele was associated with greater dilation of lateral ventricles and ventricular volume. Significant intrapair correlations were found for total intracranial area and volume, cerebellar area and white matter lesions.
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| 9. |
- Rodrigues Monge, Lucía Mercedes, 1958
(författare)
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Theoretical Studies on Electronic Structure, Spectra and Conductivity of Pristine and Alkali Doped Polyacetylene
- 1996
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis is a theoretical investigation of the electronic properties of linear polyenes to get an insight into conductive phenomena in pristine and doped polyacetylene. Conductivity in polyacetylene is a complex phenomena and cannot be treated within simple band models. Highly doped polyacetylene has many of the attributes of metals, although its conductivity does not have the dependence on temperature seen in metals. Emphasis is put on electron transfer (ET) models owing to the fact that electrons (or holes) tend to be localized. Relevant parameters for ET are calculated, such as internal reorganization energy .lambda.i and electronic coupling .DELTA. between localities. The nature of the trapping sites is investigated as well as the influence of alkali atoms in ET. The semiconductor--metal transition that appears at high doping levels is examined. One or two polyene chains are taken as model compounds for polyacetylene. In some calculations alkali metal atomswere added. Geometries are optimized keeping restrictions according to crystallographic data. Quantum chemistry methods at different levels of approximation were used. Simple tight-binding and CNDO/S semiempirical methods were used to study large systems. For smaller systems ab initio HF-SCF and correlation corrected methods were used: second-order perturbation theory (MP2), multiconfigurational-SCF (CASSCF), multiconfigurational second order perturbation (CASPT2), and state interaction based on CASSCF wave functions (CASSI) methods. It is shown that ET theory can be applied to describe the role of hopping in the electronic conductivity of polyacetylene. It is found that in CnHn+2 with even n the reorganization energy .lambda.i is much larger than in systems with odd n. Odd-n polyenes are more ready acceptors of an additional electron. The alkali atoms induces rearrangements in PA structure, and leads to a significant increase of .lambda.i the reorganization energy and the activation energy, and to a moderate increase of the coupling between localities. The tight-binding method used proves to reproduce to a high degree of accuracy the ab initio results, and allows the elucidation of the nature of solitons and polarons and the possible mechanisms for its creation. The absorption spectra band below 1 eV is related to the appearance of metallic conductivity, and consists of interchain as well as intrachain transitions.
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