| 1. |
- Yi, Chuixiang, et al.
(författare)
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Climate control of terrestrial carbon exchange across biomes and continents
- 2010
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is (1) a strong function of mean annual temperature at mid-and high-latitudes, (2) a strong function of dryness at mid-and low-latitudes, and (3) a function of both temperature and dryness around the mid-latitudinal belt (45 degrees N). The sensitivity of NEE to mean annual temperature breaks down at similar to 16 degrees C (a threshold value of mean annual temperature), above which no further increase of CO2 uptake with temperature was observed and dryness influence overrules temperature influence.
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| 2. |
- Dévai, Gergely, et al.
(författare)
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Efficient Code Generation from the High-level Domain-specific Language Feldspar for DSPs
- 2010
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Ingår i: ODES-8: 8th Workshop on Optimizations for DSP and Embedded Systems, workshop associated with IEEE/ACM International Symposium on Code Generation and Optimization (CGO).
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Konferensbidrag (refereegranskat)abstract
- Software for digital signal processors (DSPs) is traditionally highly hardware-dependent and hence porting it to new processors usually requires significant design effort. In this paper we present Feldspar (Functional Embedded Language for DSP and Parallelism), an embedded, high-level, domain-specific language for DSP algorithm design and the compilation techniques we developed for generating C code from specifications written in Feldspar. While Feldspar allows description of algorithms on specification level, we show that with the right set of abstractions and transformations this high level, functional specification can be transformed into C code that is comparable or better than reference, hand-crafted C language implementations. The Feldspar compiler is highly modular and plugin-based, hence future hardware-specific plugins will enable automatic generation of efficient, hardware-specific code. This approach enables the encapsulation of knowledge of hardware completely in the compiler and thus allows description of algorithms in completely hardware-independent, portable manner.
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| 3. |
- Gáll, Tamás, et al.
(författare)
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Heme induces endoplasmic reticulum stress (Hier stress) in human aortic smooth muscle cells
- 2018
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 9:NOV
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Tidskriftsartikel (refereegranskat)abstract
- Accumulation of damaged or misfolded proteins resulted from oxidative protein modification induces endoplasmic reticulum (ER) stress by activating the pathways of unfolded protein response. In pathologic hemolytic conditions, extracellular free hemoglobin is submitted to rapid oxidation causing heme release. Resident cells of atherosclerotic lesions, after intraplaque hemorrhage, are exposed to heme leading to oxidative injury. Therefore, we raised the question whether heme can also provoke ER stress. Smooth muscle cells are one of the key players of atherogenesis; thus, human aortic smooth muscle cells (HAoSMCs) were selected as a model cell to reveal the possible link between heme and ER stress. Using immunoblotting, quantitative polymerase chain reaction and immunocytochemistry, we quantitated the markers of ER stress. These were: phosphorylated eIF2α, Activating transcription factor-4 (ATF4), DNA-damage-inducible transcript 3 (also known as C/EBP homology protein, termed CHOP), X-box binding protein-1 (XBP1), Activating transcription factor-6 (ATF6), GRP78 (glucose-regulated protein, 78kDa) and heme responsive genes heme oxygenase-1 and ferritin. In addition, immunohistochemistry was performed on human carotid artery specimens from patients who had undergone carotid endarterectomy. We demonstrate that heme increases the phosphorylation of eiF2α in HAoSMCs and the expression of ATF4. Heme also enhances the splicing of XBP1 and the proteolytic cleavage of ATF6. Consequently, there is up-regulation of target genes increasing both mRNA and protein levels of CHOP and GRP78. However, TGFβ and collagen type I decreased. When the heme binding proteins, alpha-1-microglobulin (A1M) and hemopexin (Hpx) are present in cell media, the ER stress provoked by heme is inhibited. ER stress pathways are also retarded by the antioxidant N-acetyl cysteine (NAC) indicating that reactive oxygen species are involved in heme-induced ER stress. Consistent with these findings, elevated expression of the ER stress marker GRP78 and CHOP were observed in smooth muscle cells of complicated lesions with hemorrhage compared to either atheromas or healthy arteries. In conclusion, heme triggers ER stress in a time- and dose-dependent manner in HAoSMCs. A1M and Hpx as well as NAC effectively hamper heme-induced ER stress, supporting their use as a potential therapeutic approach to reverse such a deleterious effects of heme toxicity.
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| 4. |
- Gulyas, Katalin, et al.
(författare)
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Effects of 1-year anti-TNF-α therapies on bone mineral density and bone biomarkers in rheumatoid arthritis and ankylosing spondylitis
- 2020
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Ingår i: Clinical Rheumatology. - : Springer Science and Business Media LLC. - 0770-3198 .- 1434-9949. ; 39:1, s. 167-175
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesRheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with generalized and localized bone loss. We conducted a comprehensive study using imaging (dual-energy X-ray absorptiometry, DXA) and laboratory biomarkers in order to determine bone health and to study the effects of anti-tumor necrosis factor (TNF) biologics in RA and AS.Patients and methodsThirty-six RA and 17 AS patients undergoing 1-year etanercept (ETN) or certolizumab-pegol (CZP) therapy were studied. Bone density was assessed by DXA at baseline and after 12 months. Serum C-reactive protein (CRP), calcium, phosphate, parathyroid hormone (PTH), vitamin D3, osteocalcin, procollagen type I N-propeptide (P1NP), C-terminal telopeptide (βCTX), osteoprotegerin, sclerostin (SOST), Dickkopf-1 (DKK-1), soluble receptor activator nuclear kappa B ligand (sRANKL), and cathepsin K (cathK) levels were determined at baseline and after 6 and 12 months.ResultsTNF-α inhibition was clinically effective. Anti-TNF-α halted further bone loss over 1 year. In general, anti-TNF therapy significantly increased P1NP, SOST levels, and the P1NP/βCTX ratios, while decreased DKK-1 and CathK production at different time points in most patient subsets. In the full cohort and in RA, baseline and/or 12-month bone mineral density (BMD) at multiple sites exerted inverse relationships with CRP and βCTX, and positive correlation with SOST. In AS, L2-4 BMD after 1-year biologic therapy inversely correlated with baseline βCTX, while femoral neck BMD rather showed inverse correlations with CRP.ConclusionsAnti-TNF therapy slowed down generalized bone loss, in association with clinical improvements, in both diseases. TNF blockade may enhance bone formation and suppress joint destruction. Anti-TNF therapy may act inversely on DKK-1 and SOST. Independent predictors of BMD were SOST and βCTX in RA, whilst CRP in AS.
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| 5. |
- Kovacs-Krausz, Zoltan, et al.
(författare)
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Revealing the band structure of ZrTe5 using multicarrier transport
- 2023
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Ingår i: Physical Review B. - 2469-9969 .- 2469-9950. ; 107:7
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Tidskriftsartikel (refereegranskat)abstract
- The layered material ZrTe5 appears to exhibit several exotic behaviors, which resulted in significant interest recently, although the exact properties are still highly debated. Among these we find a Dirac/Weyl semimetallic behavior, nontrivial spin textures revealed by low-temperature transport, and a potential weak or strong topological phase. The anomalous behavior of resistivity has been recently elucidated as originating from band shifting in the electronic structure. Our work examines magnetotransport behavior in ZrTe5 samples in the context of multicarrier transport. The results, in conjunction with ab initio band structure calculations, indicate that many of the transport features of ZrTe5 across the majority of the temperature range can be adequately explained by the semiclassical multicarrier transport model originating from a complex Fermi surface.
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| 6. |
- Maróti, Zoltán, et al.
(författare)
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The genetic origin of Huns, Avars, and conquering Hungarians
- 2022
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 32:13, s. 2858-2870, 2858–2870.e1–e7
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Tidskriftsartikel (refereegranskat)abstract
- Huns, Avars, and conquering Hungarians were migration-period nomadic tribal confederations that arrived in three successive waves in the Carpathian Basin between the 5th and 9th centuries. Based on the historical data, each of these groups are thought to have arrived from Asia, although their exact origin and relation to other ancient and modern populations have been debated. Recently, hundreds of ancient genomes were analyzed from Central Asia, Mongolia, and China, from which we aimed to identify putative source populations for the above-mentioned groups. In this study, we have sequenced 9 Hun, 143 Avar, and 113 Hungarian conquest period samples and identified three core populations, representing immigrants from each period with no recent European ancestry. Our results reveal that this “immigrant core” of both Huns and Avars likely originated in present day Mongolia, and their origin can be traced back to Xiongnus (Asian Huns), as suggested by several historians. On the other hand, the “immigrant core” of the conquering Hungarians derived from an earlier admixture of Mansis, early Sarmatians, and descendants of late Xiongnus. We have also shown that a common “proto-Ugric” gene pool appeared in the Bronze Age from the admixture of Mezhovskaya and Nganasan people, supporting genetic and linguistic data. In addition, we detected shared Hun-related ancestry in numerous Avar and Hungarian conquest period genetic outliers, indicating a genetic link between these successive nomadic groups. Aside from the immigrant core groups, we identified that the majority of the individuals from each period were local residents harboring “native European” ancestry.
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| 7. |
- Wohlfahrt, Georg, et al.
(författare)
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Biotic, Abiotic, and Management Controls on the Net Ecosystem CO2 Exchange of European Mountain Grassland Ecosystems
- 2008
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Ingår i: Ecosystems. - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 11:8, s. 1338-1351
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Tidskriftsartikel (refereegranskat)abstract
- was spring and autumn for the sites characterized by summer droughts (southern sites) and (peak) summer for the Alpine and northern study sites. This general pattern was interrupted by grassland management practices, that is, mowing and grazing, when the variability in NEE explained by PPFD decreased in concert with the amount of aboveground biomass (BMag). Temperature was the abiotic influence factor that explained most of the variability in ecosystem respiration at the Alpine and northern study sites, but not at the southern sites characterized by a pronouncedThe net ecosystem carbon dioxide (CO2) exchange (NEE) of nine European mountain grassland ecosystems was measured during 2002-2004 using the eddy covariance method. Overall, the availability of photosynthetically active radiation (PPFD) was the single most important abiotic influence factor for NEE. Its role changed markedly during the course of the season, PPFD being a better predictor for NEE during periods favorable for CO2 uptake, which summer drought, where soil water availability and the amount of aboveground biomass were more or equally important. The amount of assimilating plant area was the single most important biotic variable determining the maximum ecosystem carbon uptake potential, that is, the NEE at saturating PPFD. Good correspondence, in terms of the magnitude of NEE, was observed with many (semi-) natural grasslands around the world, but not with grasslands sown on fertile soils in lowland locations, which exhibited higher maximum carbon gains at lower respiratory costs. It is concluded that, through triggering rapid changes in the amount and area of the aboveground plant matter, the timing and frequency of land management practices is crucial for the short-term sensitivity of the NEE of the investigated mountain grassland ecosystems to climatic drivers.
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| 8. |
- Cinege, Gyöngyi, et al.
(författare)
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Distinctive features of Zaprionus indianus hemocyte differentiation and function revealed by transcriptomic analysis
- 2023
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Insects have specialized cell types that participate in the elimination of parasites, for instance, the lamellocytes of the broadly studied species Drosophila melanogaster. Other drosophilids, such as Drosophila ananassae and the invasive Zaprionus indianus, have multinucleated giant hemocytes, a syncytium of blood cells that participate in the encapsulation of the eggs or larvae of parasitoid wasps. These cells can be formed by the fusion of hemocytes in circulation or originate from the lymph gland. Their ultrastructure highly resembles that of the mammalian megakaryocytes.Methods: Morphological, protein expressional, and functional features of blood cells were revealed using epifluorescence and confocal microscopy. The respective hemocyte subpopulations were identified using monoclonal antibodies in indirect immunofluorescence assays. Fluorescein isothiocyanate (FITC)-labeled Escherichia coli bacteria were used in phagocytosis tests. Gene expression analysis was performed following mRNA sequencing of blood cells.Results: D. ananassae and Z. indianus encapsulate foreign particles with the involvement of multinucleated giant hemocytes and mount a highly efficient immune response against parasitoid wasps. Morphological, protein expressional, and functional assays of Z. indianus blood cells suggested that these cells could be derived from large plasmatocytes, a unique cell type developing specifically after parasitoid wasp infection. Transcriptomic analysis of blood cells, isolated from naïve and wasp-infected Z. indianus larvae, revealed several differentially expressed genes involved in signal transduction, cell movements, encapsulation of foreign targets, energy production, and melanization, suggesting their role in the anti-parasitoid response. A large number of genes that encode proteins associated with coagulation and wound healing, such as phenoloxidase activity factor-like proteins, fibrinogen-related proteins, lectins, and proteins involved in the differentiation and function of platelets, were constitutively expressed. The remarkable ultrastructural similarities between giant hemocytes and mammalian megakaryocytes, and presence of platelets, and giant cell-derived anucleated fragments at wound sites hint at the involvement of this cell subpopulation in wound healing processes, in addition to participation in the encapsulation reaction.Conclusion: Our observations provide insights into the broad repertoire of blood cell functions required for efficient defense reactions to maintain the homeostasis of the organism. The analysis of the differentiation and function of multinucleated giant hemocytes gives an insight into the diversification of the immune mechanisms.
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| 9. |
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| 10. |
- Grzesik, Andrzej, et al.
(författare)
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Avoider-enforcer star games
- 2015
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Ingår i: Discrete Mathematics & Theoretical Computer Science. - : Discrete Mathematics and Theoretical Computer Science (DMTCS). - 1462-7264 .- 1365-8050. ; 17:1, s. 145-160
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we study (1 : b) Avoider-Enforcer games played on the edge set of the complete graph on n vertices. For every constant k≥3 we analyse the k-star game, where Avoider tries to avoid claiming k edges incident to the same vertex. We consider both versions of Avoider-Enforcer games — the strict and the monotone — and for each provide explicit winning strategies for both players. We determine the order of magnitude of the threshold biases fmonF, f-F and f+F, where F is the hypergraph of the game.
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