| 1. |
- Rogström, Lina, et al.
(författare)
-
Age hardening in arc-evaporated ZrAlN thin films
- 2010
-
Ingår i: Scripta Materialia. - Amsterdam : Elsevier Science B.V.. - 1359-6462 .- 1872-8456. ; 62:10, s. 739-741
-
Tidskriftsartikel (refereegranskat)abstract
- Zr0.44Al0.56N1.20 films were deposited by reactive arc evaporation on WC-Co substrates. As-deposited films have a defect-rich NaCl-cubic and wurtzite phase mixture. During annealing at 1100 degrees C the films undergo simultaneous recovery of the ZrN-rich c-ZrAlN nanoscale domains and formation of semicoherent w-ZrAlN nanobricks, while the excess nitrogen is released. This process results in an age hardening effect as high as 36%, as determined by nanoindentation. At 1200 degrees C, the w-AlN recrystallizes and the hardening effect is lost.
|
|
| 2. |
- Rogström, Lina, et al.
(författare)
-
Thermal stability and mechanical properties of arc evaporated ZrN/ZrAlN multilayers
- 2010
-
Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 519:2, s. 694-699
-
Tidskriftsartikel (refereegranskat)abstract
- ZrN1.20/Zr0.44Al0.56N1.20 multilayer films as well as ZrN1.17 and Zr0.44Al0.56N1.20 films were deposited by reactive arc evaporation on WC–Co substrates. Samples were post-deposition annealed for 2 h at 800–1200 °C. As-deposited and heat treated films were characterized by scanning transmission electron microscopy, X-ray diffraction and nanoindentation. The thermal stability was studied using a combination of differential scanning calorimetry, thermogravimetry, and mass spectrometry. The as-deposited Zr0.44Al0.56N1.20 film exhibits a nanocomposite structure of cubic and wurtzite ZrAlN. During annealing, the formation of ZrN- and AlN-rich domains results in age hardening of both the Zr0.44Al0.56N1.20 and the ZrN/ZrAlN multilayers. The age hardening is enhanced in the ZrN/ZrAlN multilayer due to straining of the ZrAlN sublayers in which a maximum hardness of 31 GPa is obtained after annealing at 1100 °C.
|
|
| 3. |
- Ahlgren, Bengt, et al.
(författare)
-
Experiments with Subversion Over OpenNetInf and CCNx
- 2011. - 7
-
Konferensbidrag (refereegranskat)abstract
- We describe experiences and insights from adapting the Subversion version control system to use the network service of two information-centric networking (ICN) prototypes: OpenNetInf and CCNx. The evaluation is done using a local collaboration scenario, common in our own project work where a group of people meet and share documents through a Subversion repository. The measurements show a performance benefit already with two clients in some of the studied scenarios, despite being done on un-optimised research prototypes. The conclusion is that ICN clearly is beneficial also for non mass-distribution applications.
|
|
| 4. |
- Ahlgren, Bengt, et al.
(författare)
-
Subversion over OpenNetInf and CCNx
- 2011
-
Ingår i: Proceedings - Conference on Local Computer Networks, LCN. - 9781612849287 ; , s. 1056-1063
-
Konferensbidrag (refereegranskat)abstract
- We describe experiences and insights from adapting the Subversion version control system to use the network service of two information-centric networking (ICN) prototypes: OpenNetInf and CCNx. The evaluation is done using a local collaboration scenario, common in our own project work where a group of people meet and share documents through a Subversion repository. The measurements show a performance benefit already with two clients in some of the studied scenarios, despite being done on un-optimised research prototypes. The conclusion is that ICN clearly is beneficial also for non mass-distribution applications. It was straightforward to adapt Subversion to fetch updated files from the repository using the ICN network service. The adaptation however neglected access control which will need a different approach in ICN than an authenticated SSL tunnel. Another insight from the experiments is that care needs to be taken when implementing the heavy ICN hash and signature calculations. In the prototypes, these are done serially, but we see an opportunity for parallelisation, making use of current multi-core processors.
|
|
| 5. |
- Ahlgren, Johan, et al.
(författare)
-
Camouflaged or tanned: plasticity in freshwater snail pigmentation.
- 2013
-
Ingår i: Biology letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 9:5, s. 4-20130464
-
Tidskriftsartikel (refereegranskat)abstract
- By having phenotypically plastic traits, many organisms optimize their fitness in response to fluctuating threats. Freshwater snails with translucent shells, e.g. snails from the Radix genus, differ considerably in their mantle pigmentation patterns, with snails from the same water body ranging from being completely dark pigmented to having only a few dark patterns. These pigmentation differences have previously been suggested to be genetically fixed, but we propose that this polymorphism is owing to phenotypic plasticity in response to a fluctuating environment. Hence, we here aimed to assess whether common stressors, including ultraviolet radiation (UVR) and predation, induce a plastic response in mantle pigmentation patterns of Radix balthica. We show, in contrast to previous studies, that snails are plastic in their expression of mantle pigmentation in response to changes in UVR and predator threats, i.e. differences among populations are not genetically fixed. When exposed to cues from visually hunting fish, R. balthica increased the proportion of their dark pigmentation, suggesting a crypsis strategy. Snails increased their pigmentation even further in response to UVR, but this also led to a reduction in pattern complexity. Furthermore, when exposed to UVR and fish simultaneously, snails responded in the same way as in the UVR treatment, suggesting a trade-off between photoprotection and crypsis.
|
|
| 6. |
- Ahlgren, Kerstin M, et al.
(författare)
-
Lack of evidence for a role of islet autoimmunity in the aetiology of canine diabetes mellitus
- 2014
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8, s. e105473-
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS:Diabetes mellitus is one of the most common endocrine disorders in dogs and is commonly proposed to be of autoimmune origin. Although the clinical presentation of human type 1 diabetes (T1D) and canine diabetes are similar, the aetiologies may differ. The aim of this study was to investigate if autoimmune aetiology resembling human T1D is as prevalent in dogs as previously reported.METHODS:Sera from 121 diabetic dogs representing 40 different breeds were tested for islet cell antibodies (ICA) and GAD65 autoantibodies (GADA) and compared with sera from 133 healthy dogs. ICA was detected by indirect immunofluorescence using both canine and human frozen sections. GADA was detected by in vitro transcription and translation (ITT) of human and canine GAD65, followed by immune precipitation. Sections of pancreata from five diabetic dogs and two control dogs were examined histopathologically including immunostaining for insulin, glucagon, somatostatin and pancreas polypeptide.RESULTS:None of the canine sera analysed tested positive for ICA on sections of frozen canine or human ICA pancreas. However, serum from one diabetic dog was weakly positive in the canine GADA assay and serum from one healthy dog was weakly positive in the human GADA assay. Histopathology showed marked degenerative changes in endocrine islets, including vacuolisation and variable loss of immune-staining for insulin. No sign of inflammation was noted.CONCLUSIONS/INTERPRETATIONS:Contrary to previous observations, based on results from tests for humoral autoreactivity towards islet proteins using four different assays, and histopathological examinations, we do not find any support for an islet autoimmune aetiology in canine diabetes mellitus.
|
|
| 7. |
- Ahlgren, Sara, et al.
(författare)
-
Targeting of HER2-Expressing Tumors Using 111In-ABY-025, a Second-Generation Affibody Molecule with a Fundamentally Reengineered Scaffold
- 2010
-
Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 51:7, s. 1131-1138
-
Tidskriftsartikel (refereegranskat)abstract
- Overexpression of HER2 in breast carcinomas predicts response to trastuzumab therapy. Affibody molecules based on a non-immunoglobulin scaffold have demon-strated high potential for in vivo molecular imaging of HER2-expressing tumors. Re-engineering of the molecular scaffold has led to a second generation of optimized Affibody molecules, having a surface distinctly different from the parental protein domain from staphylococcal protein A. The new tracer showed further increased melting point, stability and overall hydrophilicity compared to the parental molecule, and was shown to be more amenable for chemical peptide synthesis. The goal of this study was to assess potential effects of this extensive re-engineering on HER2 targeting, using ABY-025, a DOTA conjugated variant of the novel tracer. Methods: 111In-ABY-025 was compared with previously evaluated parent HER2-binding Affibody tracers in vitro and in vivo. The in vivo behavior was further evaluated in mice bearing SKOV-3 xenografts, in rats and in cynomolgus macaques. Results: 111In-ABY-025 bound specifically to HER2 in vitro and in vivo. Direct comparison with the previous generation of HER2-binding tracers showed that ABY-025 retained excellent targeting properties. Rapid blood clearance was shown in mice, rats and macaques. A highly specific tumor uptake of 16.7 ± 2.5 %IA/g was seen at 4 h after injection. The tumor-to-blood ratio was 6.3 at 0.5 h, 88 at 4 h, and increased up to 3 days after injection. Gamma camera imaging of tumors was already possible 0.5 h after injection. Furthermore, repeated i.v. administration of ABY-025 did not induce antibody formation in rats. Conclusions: The biodistribution of 111In-ABY-025 was in remarkably good agreement with the parent tracers, despite profound re-engineering of the non-binding surface. The molecule displayed rapid blood clearance in all species investigated and excellent targeting capacity in tumor bearing mice, leading to high tumor-to-organ-ratios and high contrast imaging shortly after injection.
|
|
| 8. |
- Hansson, Lars-Anders, et al.
(författare)
-
Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures
- 2014
-
Ingår i: Ecosphere. - : Ecological Society of America. - 2150-8925 .- 2150-8925. ; 5:9, s. 120-
-
Tidskriftsartikel (refereegranskat)abstract
- By combining a large-scale experimental assessment on timing of insect emergence with longtermmonitoring of waterfowl hatching date, we here show that insect emergence is mainly driven bytemperature, whereas there is only a weak effect of increasing spring temperatures on inter-annualvariability in observations of waterfowl chicks. Hence, a change in timing of the mass-emergence of insectsfrom lakes and wetlands, which is the crucial food source for waterfowl chicks, will likely result in aconsumer/resource mismatch in a future climate change perspective. Specifically, we experimentally showthat a moderate increase in temperature of 38C above ambient, expected to occur within 25–75 years, leadsto a considerably (2 weeks) earlier, and more pronounced, peak in insect emergence (Chironomus sp).Moreover, by utilizing long-term Citizen Science databases, ranging over several decades, we also showthat common waterfowl species are unable to significantly adjust their reproduction to fit futuretemperature increase. Hence, based on our data we predict a future mismatch between insect emergenceand waterfowl species basing their reproduction on temperature. This will have a profound impact onreproductive success and population dynamics of many aquatic birds, as well as on freshwaterbiodiversity.
|
|
| 9. |
- Hansson, Lars-Anders, et al.
(författare)
-
Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures
- 2014
-
Ingår i: Ecosphere. - : Wiley-Blackwell. - 2150-8925. ; 5:9, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- By combining a large-scale experimental assessment on timing of insect emergence with long-term monitoring of waterfowl hatching date, we here show that insect emergence is mainly driven by temperature, whereas there is only a weak effect of increasing spring temperatures on inter-annual variability in observations of waterfowl chicks. Hence, a change in timing of the mass-emergence of insects from lakes and wetlands, which is the crucial food source for waterfowl chicks, will likely result in a consumer/resource mismatch in a future climate change perspective. Specifically, we experimentally show that a moderate increase in temperature of 3 degrees C above ambient, expected to occur within 25-75 years, leads to a considerably (2 weeks) earlier, and more pronounced, peak in insect emergence (Chironomus sp). Moreover, by utilizing long-term Citizen Science databases, ranging over several decades, we also show that common waterfowl species are unable to significantly adjust their reproduction to fit future temperature increase. Hence, based on our data we predict a future mismatch between insect emergence and waterfowl species basing their reproduction on temperature. This will have a profound impact on reproductive success and population dynamics of many aquatic birds, as well as on freshwater biodiversity.
|
|
| 10. |
- Mormul, Roger Paulo, et al.
(författare)
-
Water brownification may increase the invasibility of a submerged non-native macrophyte
- 2012
-
Ingår i: Biological Invasions. - : Springer Science and Business Media LLC. - 1387-3547 .- 1573-1464. ; 14:10, s. 2091-2099
-
Tidskriftsartikel (refereegranskat)abstract
- Environmental conditions and human activities play a significant role in structuring novel assemblages of native and non-native species. Ongoing and future climatic change may alter the performance of native and non-native species and their biotic interactions. In the northern hemisphere, expected climate changes include warmer temperatures and higher precipitation, the latter of which may increase dissolved organic carbon (humic) concentrations, resulting in browner water in aquatic ecosystems (brownification). We tested the effects of elevated temperature (3 A degrees C) and brownification on native and non-native aquatic plant production in mesocosms over 56 days. Elodea canadensis, an aquatic invasive plant, had higher relative growth rate in terms of both length and weight, as well as higher weight to length ratio when grown in brown versus clear water; E. canadensis did not respond to temperature treatments. Different functional groups of native producers (phytoplankton, periphyton, macrophytes) showed different relationships to temperature and brownification treatments, with the macrophyte response being most notable because it was opposite to that of E. canadensis. Native macrophytes decreased in biomass in browner water, where they represented about 40 % of total biomass compared to 85 % in clear water. In regression analyses, E. canadensis length RGR was best predicted only by water color treatment, but biomass RGR and biomass per length were inversely correlated with native macrophyte biomass, which is consistent with competition. Our results unexpectedly showed water brownification to have more influence on lake invasion than climate warming at this temperature regime. Two pathways emerged for climate to interact with biological invasions in structuring novel communities: directly, if non-native species respond positively to climate change, and indirectly through species interactions, for instance, because water brownification impairs growth of native macrophytes and reduces biotic resistance to invasion.
|
|
