| 1. |
- Nguyen, Van-Giang, 1989-, et al.
(författare)
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On Auto-scaling and Load Balancing for User-plane Functions in a Softwarized 5G Core
- 2021
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Ingår i: Proceedings of the 2021 17th International Conference on Network and Service Management: Smart Management for Future Networks and Services, CNSM 2021. - : IEEE. - 9783903176362 ; , s. 132-138
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Konferensbidrag (refereegranskat)abstract
- In the fifth generation (5G) mobile networks, the number of user plane functions has increased, and, in contrast to previous generations. They can be deployed in a decentralized way and auto-scaled independently from their control plane functions. Moreover, the performance of the user plane functions can be boosted with the adoption of advanced acceleration techniques such as Vector Packet Processing (VPP). However, the increased number of user plane functions has also made load balancing a necessity, something we find has so far received little attention. Moreover, the introduction of VPP poses a challenge to the design of the auto-scaling of user-plane functions. In this paper, we address these two challenges by proposing a novel performance indicator for making better auto-scaling decisions, and by proposing three new dynamic load-balancing algorithms for the user plane of a VPP-based, softwarized 5G network. The novel performance indicator is estimated based on the VPP vector rate, and is used as a threshold for the auto-scaling process. The dynamic load-balancing algorithms take into account the number of bearers allocated for each user plane function and their VPP vector rate. We validated and evaluated our proposed solution in a 5G testbed. Our experiment results show that the scaling helps to reduce the packet latency for the user plane traffic, and our proposed load-balancing algorithms seem to give a better distribution of traffic load as compared to traditional static algorithms.
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| 2. |
- Nguyen, Van-Giang, 1989-, et al.
(författare)
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On Auto-scaling and Load Balancing for User-plane Gateways in a Softwarized 5G Network
- 2021
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Ingår i: Proceedings of the 2021 17th International Conference on Network and Service Management. - : IEEE. - 9783903176362 ; , s. 132-138
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Konferensbidrag (refereegranskat)abstract
- In the fifth generation (SG) mobile networks, the number of user-plane gateways has increased, and, in contrast to previous generations they can be deployed in a decentralized way and auto-scaled independently from their control-plane functions. Moreover, the performance of the user-plane gateways can be boosted with the adoption of advanced acceleration techniques such as Vector Packet Processing (VPP). However, the increased number of user-plane gateways has also made load balancing a necessity, something we find has so far received little attention. Moreover, the introduction of VPP poses a challenge to the design of the auto-scaling of user- plane gateways. In this paper, we address these two challenges by proposing a novel performance indicator for making better auto-scaling decisions, and by proposing three new dynamic load- balancing algorithms for the user plane of a VPP-based, softwarized SG network. The novel performance indicator is estimated based on the VPP vector rate and is used as a threshold for the auto-scaling process. The dynamic load-balancing algorithms take into account the number of bearers allocated for each user-plane gateway and their VPP vector rate. We validate and evaluate our proposed solution in a SG testbed. Our experiment results show that the scaling helps to reduce the packet latency for the user-plane traffic, and that our proposed load-balancing algorithms can give a better distribution of traffic load as compared to traditional static algorithms.
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| 3. |
- Anckarsäter, Henrik, 1966, et al.
(författare)
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Persistent regional frontotemporal hypoactivity in violent offenders at follow-up.
- 2007
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Ingår i: Psychiatry research. - : Elsevier BV. - 0165-1781 .- 0925-4927 .- 1872-7123. ; 156:1, s. 87-90
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Tidskriftsartikel (refereegranskat)abstract
- Since cross-sectional brain-imaging studies demonstrating frontotemporal cerebral hypoactivity in violent offenders have generally been carried out around the time of trial and sentencing, the findings might be influenced by the stressful situation of the subjects. It seems that no group of offenders with this finding has yet been followed longitudinally. We have re-examined nine offenders convicted of lethal or near-lethal violence in whom single photon emission tomography (SPECT) previously had demonstrated frontotemporal hypoperfusion. The mean interval between the initial and the follow-up examination was 4 years. The initially observed hypoactivity was found to have remained virtually unchanged at follow-up: no mean change in the group exceeded 5% in 12 assessed regions of interest. Although preliminary due to the small sample size, this study suggests that frontotemporal brain hypoactivity is a trait rather than a state in perpetrators of severe violent crimes.
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| 4. |
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| 5. |
- Björklund, Gunilla, 1973-, et al.
(författare)
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Säkerhet och trygghet på pendeltågsstationer
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 110-111-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Obehöriga spårbeträdanden kan leda till allvarliga personskador och är dessutom mycket punktlighetsstörande för järnvägssystemet. En del stationer har omfattande problem med obehöriga i spår. Att rikta åtgärder mot stationsområden är därför viktigt för att minska antalet skadade och omkomna i järnvägssystemet och för att öka punktligheten. Inom det branschövergripande arbetet Tillsammans för Tåg i Tid pekade man ut pendeltågsstationerna Årstaberg, Upplands Väsby och Järna som belastade platser.Syften med den här studien var att:studera säkerheten på de tre stationerna ovan samt att studera resenärers och personals förslag på vad som kan förbättras på dessa stationer. Vi studerade även tryggheten på stationerna.Utvärdera de fysiska åtgärder som Trafikverket genomför på de tre stationerna under projektets tidsram. Även Södra station studerades.I denna presentation kommer endast resultat från det första syftet presenteras. I projektet har följande aktiviteter genomförts:Platsbesök på stationerna, inklusive samtal med personal på plats, för att dokumentera utformning av och brister på stationerna.Analys av data över antal obehöriga spårbeträdanden och påkörningar vid dessa stationer samt förseningar som en följd av dessa händelser.Analys av händelser som inkommit till Trygghetscentralen gällande de tre stationerna.Resenärsenkät kring upplevd trygghet, säkerhet samt information på de tre pendeltågsstationerna.Rekrytering skedde genom anslag på berörda stationer, annons på Facebook samt på Instagram.Personalenkät (med liknande innehåll som i resenärsenkäten) riktad till lokalvårdare, ordningsvakter och stationsvärdar (spärrvakter).Intervjuer med pendeltågsförare, stationschefer och entreprenörer.Omkring 90% av de deltagande resenärerna svarade att de visste att det är olagligt att befinna sig i spårområdet redan innan de deltog i studien. I Årstaberg upplevde resenärerna att stationen var mindre säker (med tanke på risken att ramla ner på spåret) än vad man gjorde i Järna. I övrigt var ingen skillnad i upplevd säkerhet mellan stationerna. När det gäller hur trygga stationerna upplevdes av resenärerna (med avseende på risken för rån och överfall) var det ingen skillnad mellan stationerna på dagtid. På kvällar/nätter upplevdes dock Upplands Väsby som mer otrygg än Årstaberg.
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| 6. |
- Björklund, Gunilla, 1973-, et al.
(författare)
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Utvärdering av åtgärder för säkerhet och trygghet på pendeltågsstationer
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Obehöriga spårbeträdanden är olagliga, vållar stora förseningar på järnvägen och innebär ett allvarligt arbetsmiljöproblem för tågförarna. En del obehöriga spårbeträdanden leder dessutom till personpåkörningar, vilket står för den största andelen dödsfall inom järnvägen. Vissa stationer har omfattande problem med obehöriga spårbeträdanden och personpåkörningar och därför är riktade åtgärder mot stationsområden viktiga.Syftet med projektet var att:• studera tryggheten och säkerheten på de tre pendeltågsstationerna Järna, Upplands Väsby och Årstaberg innan någon åtgärd genomförts och studera resenärers och personals förslag på vad som kan förbättras,• utvärdera de fysiska åtgärder som Trafikverket genomförde på dessa stationer, under förutsättning att åtgärderna implementerades under projektets tidsram (endast Järna station uppfyllde detta kriterium),• utvärdera de implementerade åtgärderna på Stockholms södra station.I projektet genomfördes strukturerade observationer, enkätstudier med resenärer och personal, intervjuer med personal, analys av händelser som inkommit till SL:s trygghetscentral, databasanalys över antal obehöriga spårbeträdanden och personpåkörningar samt videoanalys över antal obehöriga i spår.Resultaten visar att det skett en signifikant minskning av antal obehöriga spårbeträdanden/personpåkörningar på Järna station efter att de fysiska åtgärderna med staket, nya hajtänder, varningsskyltar och klistermärken implementerades. Vid Upplands Väsby och Årstaberg skedde ingen minskning av antal händelser under samma tidsperiod, vilket tyder på att minskningen i Järna beror på något annat än en allmän trend.Vi fann även en stor och signifikant minskning av antal obehöriga spårbeträdanden på Stockholms södra station, samt en signifikant minskning av antalet personpåkörningar på stationen och förseningar på grund av obehöriga i spår, personpåkörningar och suicidhändelser. Detta indikerar att åtgärden med längsgående staket i plattformsände (inklusive pyramidmattor, hajtänder och skyltar) har haft en effekt.De implementerade åtgärderna på Järna station och Stockholms södra station har varit enkla och relativt billiga samtidigt som resultaten tyder på att de haft effekt. Denna typ av åtgärder, som dessutom kan användas i kombination med varandra, är en viktig strategi för att skyndsamt minska antalet obehöriga spårbeträdanden och personpåkörningar.
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| 7. |
- Björkman, Lena, 1965, et al.
(författare)
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Neutrophil recruitment to inflamed joints can occur without cellular priming.
- 2019
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Ingår i: Journal of leukocyte biology. - 1938-3673. ; 105:6, s. 1123-1130
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Tidskriftsartikel (refereegranskat)abstract
- Recruitment of neutrophils from blood to tissues is a cardinal event in inflammation during which neutrophils switch from a resting, naive state to a preactivated, primed phenotype; the priming process is characterized by alterations in the composition of cell surface adhesins, for example, shedding of l-selectin and mobilization of granule-stored integrins to the cell surface. Ligation of chemotactic receptors and interactions with the endothelial lining are established triggers of neutrophil priming and in line with this, in vivo transmigrated neutrophils obtained from tissues are typically highly primed. We here characterize the priming of neutrophils brought about by in vivo recruitment from blood to inflamed joints by the analyses of synovial fluid and blood from patients with inflammatory arthritis. For comparisons, we used controlled in vivo models of neutrophil transmigration to skin of healthy subjects. In contrast to the residing view and in vivo transmigrated neutrophils from skin models, neutrophils from synovial fluid were often surprisingly resting and phenotypically very similar to naive cells isolated from peripheral blood; synovial fluid cells often retained l-selectin and had undergone minimal up-regulation of integrin receptors. In complete agreement with our in vivo findings, cell-free synovial fluid was potently chemotactic without triggering alteration of surface receptors also in vitro. We conclude that tissue recruitment of neutrophils does not by default trigger l-selectin shedding and granule mobilization, and the chemoattractant(s) guiding neutrophils to synovial fluid apparently operate without inducing cellular priming.
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| 8. |
- Björkman, Lena, 1965, et al.
(författare)
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The Neutrophil Response Induced by an Agonist for Free Fatty Acid Receptor 2 (GPR43) Is Primed by Tumor Necrosis Factor Alpha and by Receptor Uncoupling from the Cytoskeleton but Attenuated by Tissue Recruitment
- 2016
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Ingår i: Molecular and Cellular Biology. - : Informa UK Limited. - 0270-7306 .- 1098-5549. ; 36:20, s. 2583-2595
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Tidskriftsartikel (refereegranskat)abstract
- Ligands with improved potency and selectivity for free fatty acid receptor 2 (FFA2R) have become available, and we here characterize the neutrophil responses induced by one such agonist (Cmp1) and one antagonist (CATPB). Cmp1 triggered an increase in the cytosolic concentration of Ca2+, and the neutrophils were then desensitized to Cmp1 and to acetate, a naturally occurring FFA2R agonist. The antagonist CATPB selectively inhibited responses induced by Cmp1 or acetate. The activated FFA2R induced superoxide anion secretion at a low level in naive blood neutrophils. This response was largely increased by tumor necrosis factor alpha (TNF-alpha) in a process associated with a recruitment of easily mobilizable granules, but neutrophils recruited to an aseptic inflammation in vivo were nonresponding. Superoxide production induced by Cmp1 was increased in latrunculin A-treated neutrophils, but no reactivation of desensitized FFA2R was induced by this drug, suggesting that the cytoskeleton is not directly involved in terminating the response. The functional and regulatory differences between the receptors that recognize short-chain fatty acids and formylated peptides, respectively, imply different roles of these receptors in the orchestration of inflammation and confirm the usefulness of a selective FFA2R agonist and antagonist as tools for the exploration of the precise role of the FFA2R.
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| 9. |
- Björnsdottir, Halla, et al.
(författare)
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Phenol-soluble Modulin α Peptide Toxins from aggressive Staphylococcus aureus induce rapid Formation of neutrophil extracellular Traps through a reactive Oxygen species-independent Pathway
- 2017
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils have the ability to capture and kill microbes extracellularly through the formation of neutrophil extracellular traps (NETs). These are DNA and protein structures that neutrophils release extracellularly and are believed to function as a defense mechanism against microbes. The classic NET formation process, triggered by, e.g., bacteria, fungi, or by direct stimulation of protein kinase C through phorbol myristate acetate, is an active process that takes several hours and relies on the production of reactive oxygen species (ROS) that are further modified by myeloperoxidase (MPO). We show here that NET-like structures can also be formed by neutrophils after interaction with phenol-soluble modulin alpha (PSM alpha) that are cytotoxic membrane-disturbing peptides, secreted from community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). The PSMa-induced NETs contained the typical protein markers and were able to capture microbes. The PSMa-induced NET structures were disintegrated upon prolonged exposure to DNase-positive S. aureus but not on exposure to DNase-negative Candida albicans. Opposed to classic NETosis, PSMa-triggered NET formation occurred very rapidly, independently of ROS or MPO, and was also manifest at 4 degrees C. These data indicate that rapid NETs release may result from cytotoxic membrane disturbance by PSMa peptides, a process that may be of importance for CA-MRSA virulence.
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| 10. |
- Björstad, Åse, 1976, et al.
(författare)
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The host defense peptide LL-37 selectively permeabilizes apoptotic leukocytes.
- 2009
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Ingår i: Antimicrobial agents and chemotherapy. - 1098-6596. ; 53:3, s. 1027-38
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Tidskriftsartikel (refereegranskat)abstract
- LL-37 is a cationic host defense peptide that is highly expressed during acute inflammation and that kills bacteria by poorly defined mechanisms, resulting in permeabilization of microbial membranes. High concentrations of LL-37 have also been reported to have cytotoxic effects against eukaryotic cells, but the peptide is clearly capable of differentiating between membranes with different compositions (eukaryotic versus bacterial membranes). Eukaryotic cells such as leukocytes change their membrane composition during apoptotic cell death, when they are turned into nonfunctional but structurally intact entities. We tested whether LL-37 exerted specific activity on apoptotic cells and found that the peptide selectively permeabilized the membranes of apoptotic human leukocytes, leaving viable cells unaffected. This activity was seemingly analogous to the direct microbicidal effect of LL-37, in that it was rapid, independent of known surface receptors and/or active cell signaling, and inhibitable by serum components such as high-density lipoprotein. A similar selective permeabilization of apoptotic cells was recorded for both NK cells and neutrophils. In the latter cell type, LL-37 permeabilized both the plasma and granule membranes, resulting in the release of both lactate dehydrogenase and myeloperoxidase. Apoptosis is a way for inflammatory cells to die silently and minimize collateral tissue damage by retaining tissue-damaging and proinflammatory substances within intact membranes. Permeabilization of apoptotic leukocytes by LL-37, accompanied by the leakage of cytoplasmic as well as intragranular molecules, may thus shift the balance between pro- and anti-inflammatory signals and in this way be of importance for the termination of acute inflammation.
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