| 1. |
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| 2. |
- Andersson, G., et al.
(författare)
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Cyber-security of SCADA systems
- 2012
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Ingår i: 2012 IEEE PES Innovative Smart Grid Technologies, ISGT 2012. - : IEEE. - 9781457721588 ; , s. 6175543-
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Konferensbidrag (refereegranskat)abstract
- After a general introduction of the VIKING EU FP7 project two specific cyber-attack mechanisms, which have been analyzed in the VIKING project, will be discussed in more detail. Firstly an attack and its consequences on the Automatic Generation Control (AGC) in a power system are investigated, and secondly the cyber security of State Estimators in SCADA systems is scrutinized.
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| 3. |
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| 4. |
- Dalhammar, Karin, et al.
(författare)
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Health care utilization among patients with oesophageal and gastric cancer : the impact of initial treatment strategy and assignment of a contact nurse
- 2021
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Ingår i: BMC Health Services Research. - : Springer Science and Business Media LLC. - 1472-6963. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients diagnosed with oesophageal and gastric cancer face a poor prognosis and numerous challenges of symptom management, lifestyle adjustments and complex treatment regimens. The multifaceted care needs and rapid disease progression reinforce the need for proactive and coherent health care. According to the national cancer strategy, providing coherent health care and palliative support is an area of priority. More knowledge is needed about health care utilization and the characteristics of the health care service in order to understand the readiness, accessibility and quality of current health care. The aim of this study was to describe individuals’ health care use from the time of treatment decision until death, and investigate the impact of the initial treatment strategy and assignment of a contact nurse (CN) on health care use among patients with oesophageal and gastric cancer. Methods: This population-based cohort study included patients who died from oesophageal and gastric cancer in Sweden during 2014–2016. Through linking data from the National Register for Oesophageal and Gastric Cancer, the National Cause of Death Register, and the National Patient Register, 2614 individuals were identified. Associations between the initial treatment strategy and CN assignment, and health care use were investigated. Adjusted incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were calculated using Poisson regression. Results: Patients receiving palliative treatment and those receiving no tumour-directed treatment had a higher IRR for unplanned hospital stays and unplanned outpatient care visits compared with patients who received curative treatment. Patients receiving no tumour-directed treatment also had a lower IRR for planned hospital stays and planned outpatient care visits compared with patients given curative treatment. Compared with this latter group, patients with palliative treatment had a higher IRR for planned outpatient care visits. Patients assigned a CN had a higher IRR for unplanned hospital stays, unplanned outpatient care visits and planned outpatient care visits, compared with patients not assigned a CN. Conclusions: A palliative treatment strategy and no tumour-directed treatment were associated with higher rates of unplanned health care compared with a curative treatment strategy, suggesting that a proactive approach is imperative to ensure quality palliative care.
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| 5. |
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| 6. |
- Dalteg, Tomas, et al.
(författare)
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The heart is a representation of life : an exploration of illness beliefs in couples living with atrial fibrillation
- 2017
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Ingår i: Journal of Clinical Nursing. - : Wiley-Blackwell. - 0962-1067 .- 1365-2702. ; 16:Suppl. 1, s. S41-S41
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Tidskriftsartikel (refereegranskat)abstract
- Aims and objectives. To explore illness beliefs in couples where one spouse has atrial fibrillation.& para;& para;Background. Beliefs are the lenses through which we view the world, guiding our behaviour and constructing our lives. Couples evolve an ecology of beliefs from their interaction whereby their actions and choices arise from their beliefs. Atrial fibrillation is a common cardiac arrhythmia that has implications for both patients and partners. A couple's illness beliefs play an important role in convalescence and illness management, and no previous studies have explored illness beliefs in couples living with atrial fibrillation.& para;& para;Design. A qualitative hermeneutic design.& para;& para;Methods. Data collection constituted in-depth interviews with nine couples (patient and partner together). Hermeneutic philosophy as described by Gadamer was used to interpret and to understand illness beliefs in couples living with atrial fibrillation.& para;& para;Results. The findings revealed both core illness beliefs and secondary illness beliefs. From the core illness belief 'The heart is a representation of life', two secondary illness beliefs were derived: atrial fibrillation is a threat to life and atrial fibrillation can and must be explained. From the core illness belief 'Change is an integral part of life', two secondary illness beliefs were derived: atrial fibrillation is a disruption in our lives and atrial fibrillation will not interfere with our lives. Finally, from the core illness belief 'Adaptation is fundamental in life', two secondary illness beliefs were derived: atrial fibrillation entails adjustment in daily life and atrial fibrillation entails confidence in and adherence to professional care.& para;& para;Conclusion. Couples' interaction has developed mutual illness beliefs regarding atrial fibrillation that guide them in their daily lives and influence their decisions. The adoption of a family-centred perspective in cardiovascular care settings is warranted.
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| 7. |
- Dán, György, et al.
(författare)
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Challenges in Power System Information Security
- 2012
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Ingår i: IEEE Security and Privacy. - : IEEE Computer Society. - 1540-7993 .- 1558-4046. ; 10:4, s. 62-70
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Tidskriftsartikel (refereegranskat)abstract
- Achieving all-encompassing component-level security in power system IT infrastructures is difficult, owing to its cost and potential performance implications.
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| 8. |
- Dán, György, et al.
(författare)
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Power-system state-estimation security : Attacks and protection schemes
- 2010
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Ingår i: Smart Grid Communications and Networking. - : Cambridge University Press. - 9781139013468 - 9781107014138 ; , s. 388-412
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction Supervisory control and data acquisition (SCADA) systems are widely used to monitor and control large-scale transmission power grids. Monitoring traditionally involves the measurement of voltage magnitudes and power flows; these data are collected by meters located in substations. In order to deliver the measured data from the substations to the control centre, the measurement data measured by meters in the same substation are multiplexed by a remote terminal unit (RTU) [1, 2]. Because electric power transmission systems extend over large geographical areas, typically entire countries, wide-area networks (WANs) are used to deliver the multiplexed measurement data from the substations to the control centre. For large-scale transmission grids it is often not feasible to measure all power flows and voltages of interest. Furthermore, the measurements are often noisy. Therefore the measurement data are usually fed into a model-based state estimator (SE) at the control centre, which is used to estimate the complete physical state (complex bus voltages) of the power grid. The SE is used to identify faulty equipment and corrupted measurement data through the so-called bad-data detection (BDD) system. Apart from BDD, the state estimate is used by the human operators and by the energy-management systems (EMS) found in modern SCADA systems, such as optimal power flow analysis, and contingency analysis (CA), see for example [1]. Future power grids will be even more dependent on accurate state estimators to fulfil their task of optimally and dynamically routing power flows, because clean renewable power generation tends to be less predictable than nonrenewable power generation.
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| 9. |
- Dán, György, et al.
(författare)
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Stealth attacks and protection schemes for state estimators in power systems
- 2010
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Ingår i: 2010 1st IEEE International Conference on Smart Grid Communications, SmartGridComm 2010. - : IEEE. - 9781424465125 ; , s. 214-219
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Konferensbidrag (refereegranskat)abstract
- State estimators in power systems are currently used to, for example, detect faulty equipment and to route power flows. It is believed that state estimators will also play an increasingly important role in future smart power grids, as a tool to optimally and more dynamically route power flows. Therefore security of the estimator becomes an important issue. The estimators are currently located in control centers, and large numbers of measurements are sent over unencrypted communication channels to the centers. We here study stealthy false-data attacks against these estimators. We define a security measure tailored to quantify how hard attacks are to perform, and describe an efficient algorithm to compute it. Since there are so many measurement devices in these systems, it is not reasonable to assume that all devices can be made encrypted overnight in the future. Therefore we propose two algorithms to place encrypted devices in the system such as to maximize their utility in terms of increased system security. We illustrate the effectiveness of our algorithms on two IEEE benchmark power networks under two attack and protection cost models.
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| 10. |
- Liljendahl, Tove Sandberg, et al.
(författare)
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Quantification of ultraviolet radiation induced DNA damage in the urine of Swedish adults and children following exposure to sunlight
- 2012
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Ingår i: Biomarkers. - 1354-750X .- 1366-5804. ; 17:7, s. 634-641
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Tidskriftsartikel (refereegranskat)abstract
- Context: DNA damage following exposure to ultraviolet radiation (UVR) is important in skin cancer development. The predominant photoproduct, cyclobutane thymine dimer (T=T), is repaired and excreted in the urine, where it provides a biomarker of exposure. Objective: To quantify urinary T=T levels after recreational sunlight exposure in adults and children. Methods: Average UVR doses were measured with personal dosimeters. Urinary T=T was analysed with P-32-postlabelling. Results: Background levels of T=T increased significantly following exposure to sunlight. Amounts of T=T in urine of children and adults were not significantly different after adjusting for area of skin exposed and physiological differences. UVR dose and amounts of T=T correlated for both adults and children. Conclusion: Recreational exposure to sunlight in Sweden induces levels of DNA damage, clearly detectable in urine.
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| 11. |
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| 12. |
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| 13. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten : 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
- 2022
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Ingår i: Aftonbladet. - : Aftonbladet. ; :2022-12-07
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Vi, 1 620 forskare samt lärare vid universitet och högskolor, är eniga med de unga bakom Auroramålet: De drabbas och riskerar att drabbas allvarligt av klimatkrisen under sin livstid. De klimatåtgärder vi vidtar i närtid avgör deras framtid. Sverige måste ta ansvar och göra sin rättvisa andel av det globala klimatarbetet. I strid med Parisavtalet ökar utsläppen av växthusgaser i en takt som gör att 1,5-gradersmålet kan överskridas om några år. De globala effekterna blir allt mer synliga med ständiga temperaturrekord, smältande isar, havshöjning och extremväder som torka, förödande bränder och skyfall med enorma översvämningar, som i Pakistan nyligen. Försörjningen av befolkningen utsätts för allvarliga hot i många länder.Minskningen av den biologiska mångfalden är extrem. Klimatkrisen är enligt WHO det största hotet mot människors hälsa i hela världen och barn utgör en särskilt sårbar grupp. Med Sveriges nordliga läge sker uppvärmningen här dubbelt så fort som det globala genomsnittet. Det förskjuter utbredningsområden för växtlighet och sjukdomsbärande insekter och ökar förekomsten av extremväder såsom värmeböljor, skogsbränder och översvämningar samt av många olika sorters infektioner och allergier. När extremväder ökar, ökar även stressen och risken för mental ohälsa. Värmeböljor ökar risken för sjukdom och död hos sårbara grupper som äldre, små barn och personer med kroniska sjukdomar. De negativa effekterna på hälsan kommer att öka i takt med klimatkrisen och barn riskerar att drabbas av ackumulerade negativa hälsoeffekter under hela sina liv. Redan i dag är mer än hälften av unga mellan 12 och 18 år i Sverige ganska eller mycket oroliga för klimat och miljö. Detta är förståeligt när våra beslutsfattare inte gör vad som krävs.Den juridiska och moraliska grunden för arbetet mot klimatförändringarna är att varje land måste göra sin rättvisa andel av det globala klimatarbetet. Centralt i det internationella klimatramverket är att rika länder med höga historiska utsläpp, däribland Sverige, måste gå före resten av världen. Dessa länder måste också bidra till att finansiera klimatomställningen i länderna i det Globala Syd, som är minst ansvariga för klimatkrisen men drabbas hårdast. Denna rättviseprincip är tydlig i Parisavtalet och var en het diskussionsfråga under COP27 i Sharm el-Sheikh, men lyser med sin frånvaro i det svenska klimatarbetet. Sverige har satt mål för att minska sina utsläpp. Men de är helt otillräckliga: minskningstakten är för låg och målen tillåter samtidigt att åtgärder skjuts på framtiden. Dessutom exkluderas merparten av Sveriges utsläpp från de svenska nationella utsläppsmålen; bland annat utelämnas utsläpp som svensk konsumtion orsakar utanför Sveriges gränser, utsläpp från utrikes transporter och utsläpp från markanvändning och skogsbruk, exempelvis utsläpp från förbränning av biobränslen eller utsläpp från dikade våtmarker (Prop. 2016/17:146 s.25-28).Sverige saknar dessutom ett eget mål för att öka upptaget av växthusgaser genom utökat skydd och restaurering av ekosystem, något som krävs för att begränsa de värsta konsekvenserna av klimatkrisen (IPCC s.32). Trots dessa låga ambitioner misslyckas Sverige med att nå sina utsläppsmål, konstaterar både Klimatpolitiska rådet och Naturvårdsverket. En klimatpolitik i linje med Parisavtalet kräver både att alla typer av växthusgasutsläpp minskar samtidigt som – inte i stället för – upptaget av växthusgaser maximeras: i dag misslyckas Sverige på bägge fronter.Slutsatsen är tydlig. Sverige vidtar inte de åtgärder som krävs för att skydda barns och ungdomars rättigheter enligt Europakonventionen till skydd för de mänskliga rättigheterna. Detta medför allvarliga risker för liv och hälsa för unga generationer, människor i andra länder och särskilt utsatta grupper. Detta kan inte fortsätta. Därför ställer vi oss bakom Auroras krav att Sverige börjar göra sin rättvisa andel och omedelbart sätter igång ett omfattande och långtgående klimatarbete som vilar på vetenskaplig grund och sätter rättvisa i centrum.
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| 14. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
-
Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 15. |
- Mosavi, Firas, et al.
(författare)
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Whole-Body Diffusion-Weighted MRI Compared With 18F-NaF PET/CT for Detection of Bone Metastases in Patients With High-Risk Prostate Carcinoma
- 2012
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Ingår i: American Journal of Roentgenology. - 0361-803X .- 1546-3141. ; 199:5, s. 1114-1120
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:The purpose of this study was to evaluate the accuracy of whole-body diffusion-weighted MRI (DWI) and 18F-NaF PET/CT for detection of bone metastases in patients with high-risk prostate cancer.SUBJECTS AND METHODS:Both patient- and lesion-based analyses were performed on 49 consecutive patients (median age, 67 years; age range, 57-80 years) with recently diagnosed high-risk prostate cancer. All patients underwent bone scintigraphy, whole-body MRI including DWI and 18F-NaF PET/CT before treatment. Bone scintigraphy, conventional MR images, and follow-up images were used as the standard of reference to evaluate 18F-NaF PET/CT and DWI.RESULTS:On patient-based analysis, five patients had skeletal metastases on reference imaging that both DWI and 18F-NaF PET/CT could verify, and 18F-NaF PET/CT and DWI showed false-positive findings in four and one patient, respectively. With lesion-based analysis, 18F-NaF PET/CT and DWI showed nine and five true-positive lesions, zero and four false-negative lesions, and seven and two false-positive lesions, respectively. Two patients with uncountable bone metastases were analyzed separately. In these patients, 18F-NaF PET/CT showed more bone metastases than did DWI.CONCLUSION:We believe 18F-NaF PET/CT is a sensitive modality for detection of bone metastases caused by prostate cancer. Whole-body DWI shows a higher specificity but lower sensitivity than 18F-NaF PET/CT. Future studies with a larger patient cohort along with analyses of costs and clinical availability are needed before implementation of these methods can be considered.
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| 16. |
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| 17. |
- Nordmark, Johanna, et al.
(författare)
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Assessment of intravascular volume by transthoracic echocardiography during therapeutic hypothermia and rewarming in cardiac arrest survivors
- 2009
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 80:11, s. 1234-1239
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To study haemodynamic effects and changes in intravascular volume during hypothermia treatment, induced by ice-cold fluids and maintained by ice-packs followed by rewarming in patients after resuscitation from cardiac arrest. MATERIALS AND METHODS: In 24 patients following successful restoration of spontaneous circulation (ROSC), hypothermia was induced with infusion of 4 degrees C normal saline and maintained with ice-packs for 26 h after ROSC. This was followed by passive rewarming. Transthoracic echocardiography was performed at 12, 24 and 48 h after ROSC to evaluate ejection fraction and intravascular volume status. Central venous pressure (CVP), central venous oxygen saturation (ScvO(2)) and serum lactate were measured. Fluid balance was calculated. RESULTS: Twelve hours after ROSC, two separate raters independently estimated that 10 and 13 out of 23 patients had a decreased intravascular volume using transthoracic echocardiography. After 24 and 48 h this number had increased further to 14 and 13 out of 19 patients and 13 and 12 out of 21 patients. Calculated fluid balance was positive (4000 ml the day 1 and 2500 ml day 2). There was no difference in ejection fraction between the recording time points. Serum lactate and ScvO(2) were in the normal range when echocardiography exams were performed. CVP did not alter over time. CONCLUSIONS: Our results support the hypothesis that inducing hypothermia following cardiac arrest, using cold intravenous fluid infusion does not cause serious haemodynamic side effects. Serial transthoracic echocardiographic estimation of intravascular volume suggests that many patients are hypovolaemic during therapeutic hypothermia and rewarming in spite of a positive fluid balance.
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| 18. |
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| 19. |
- Olsson, Lina, et al.
(författare)
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Automatiserade logistiktjänster (AutoLog)
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sammanfattning Utifrån bl. a. Sveriges transportpolitiska mål finns det ett stort behov av och potential i att öka godstransportsystemets automatisering av de betjänande logistikprocesserna i någon del av värdekedjan avseende materialhantering, fysisk transport och informationshantering enskilt eller i kombination. Målet för denna förstudie benämnd automatiserade logistiktjänster har varit att identifiera ett antal ”Case” där automatisering ger möjlighet till effektivisering, och där det finns aktörer som är beredda att driva innovationsprojekt för att ta tillvara dessa möjligheter. Ett tiotal idéer till sådana projekt har identifierats med intressentuppskattningar av potential, behov av ny teknik och nödvändiga aktörskonstellationer samt förslag till fortsatta steg, varav ett redan har konkretiserats i ett förslag till Drive Sweden. Målet har också varit att kartlägga state of the art samt pågående och avslutade projekt inom denna domän. För att klara detta har en ny strukturering av området automatiserade logistiktjänster utifrån ett verksamhetsperspektiv utvecklats där de olika logistikprocesserna kopplats ihop för ett antal strategiska behovsområden. Resultatet av identifieringen visar i stort att det saknas automatiseringsaktiviteter i flera områden med stor potential vilket till del kan bero på svårigheter att organisera alla de aktörer och intressenter som krävs för att få resultat. I de här föreslagna projekten finns flera av de typer av aktörer som krävs identifierade. Eftersom arbetet ofta kräver riskfylld forskning och utveckling samt möjligheterna till implementering är oklar behövs offentlig medfinansiering i arbetet.
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| 20. |
- Pontoppidan, K., et al.
(författare)
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In vitro and in vivo degradation of myo-inositol hexakisphosphate by a phytase from Citrobacter braakii
- 2012
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Ingår i: Archives of Animal Nutrition. - 1477-2817 .- 1745-039X. ; 66:6, s. 431-444
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Tidskriftsartikel (refereegranskat)abstract
- Phytases (EC 3.1.3) are widely used in animal feed to increase the availability of phosphorus and decrease the anti nutritive effect of myo-inositol hexakisphosphate (InsP(6)). The aim of this work was to investigate the stereospecific degradation of InsP(6) in vitro and in vivo by a phytase from Citrobacter braakii (C. braakii), and to study gastric survival of the phytase as well as the site of action in the gastrointestinal tract. The in vitro results showed that the C. braakii phytase belongs to the group of 6-phytases (EC 3.1.3.26). However, in approximately one out of 10 instances the phytase initiated hydrolysis at the D-3 (L-1) position, demonstrating that phytase specificity is not unambiguous. Following the main degradation pathway, InsP(6) was degraded by stepwise removal of the phosphate groups on positions 6/1/5. The stereospecificity was found to be similar under in vitro and in vivo conditions. The phytase was found to be stable in the gastric environment and to be active in the stomach and possibly also in the proximal small intestine. While InsP(4) was accumulated under in vitro conditions this was not the case in vivo, where both InsP(5) and InsP(4) were seen to be hydrolysed in the small intestine, possibly as a combined action of the C. braakii phytase and endogenous phosphatases present in the mucosa. The ability of the C. braakii phytase to focus its activity on degrading InsP(6) to InsP(4) is believed to be a favourable complement to the endogenous phosphatases.
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| 21. |
- Pontoppidan, Katrine, 1976, et al.
(författare)
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Interaction of phytate with protein and minerals in a soybean-maize meal blend depends on pH and calcium addition
- 2007
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 87:10, s. 1886-1892
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate possible interactions of phytate with protein and minerals in simplified animal diets, studies were conducted on the solubility of endogenous phytate, protein and essential minerals in a soybean-maize meal blend within a physiological relevant pH range. The blend was mixed with water for 10 min and then allowed to incubate at 40 degrees C (30 min) after adjustment of the pH. Finally, soluble phytate, protein, zinc, manganese and iron were determined. Phytate and mineral solubility was highly influenced by pH whereas protein solubility was less affected. Addition of 5 g Ca2+ kg(-1) drastically reduced the solubility of phytate, zinc, manganese and iron at pH above 4.4, indicating that the formation of insoluble phytate-mineral complexes is increased in the presence of calcium. The action of pepsin increased the solubility of protein and phytate at pH below 4, indicating that insoluble phytate-protein complexes are present at low pH. Calcium had the same solubilising effect as pepsin at pH 2-4 but to a lesser degree.
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| 22. |
- Pontoppidan, Katrine, 1976, et al.
(författare)
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Peniophora lycii phytase is stabile and degrades phytate and solubilises minerals in vitro during simulation of gastrointestinal digestion in the pig
- 2007
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 87:14, s. 2700-2708
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Microbial phytases (EC 3.1.3) are widely used in diets for monogastric animals to hydrolyse phytate present in the feed and thereby increase phosphorus and mineral availability. Previous work has shown that phytate solubility is strongly affected by calcium in the feed and by pH in the gastrointestinal (GI) tract, which may have an effect on phytase efficacy. An in vitro model simulating the GI tract of pigs was used to study the survival of Peniophora lycii phytase and the effect of the phytase on phytate degradation, inositol phosphate formation and mineral solubilisation during in vitro digestion of a 30:70 soybean meal/maize meal blend with different calcium levels.RESULTS: The phytase retained 76 and 80% of its initial activity throughout the gastric in vitro digestion. Total phytate hydrolysis by P. lycii phytase was in the same range at total calcium levels of 1.2 and 6.2 mg g(-1) dry matter (DM), despite very large differences in phytate solubility at these calcium levels. However, at 11.2 and 21.2 mg Ca g(-1) DM, phytate hydrolysis was significantly lower. The amount of soluble mineral was generally increased by P. lycii phytase.CONCLUSION: Stability of P. lycii phytase during gastric digestion was not found to be critical for phytate hydrolysis. Furthermore, original phytate solubility was not an absolute requirement for phytate degradation; phytate solubility seemed to be in a steady state, allowing insoluble phytate to solubilise as soluble phytate was degraded. This is new and interesting knowledge that adds to the current understanding of phytate-phytase interaction.
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| 23. |
- Pontoppidan, Katrine, 1976, et al.
(författare)
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The type of thermal feed treatment influences the inositol phosphate composition
- 2007
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Ingår i: Animal Feed Science and Technology. - : Elsevier BV. - 0377-8401. ; 132:1-2, s. 137-147
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Tidskriftsartikel (refereegranskat)abstract
- The content and composition of inositol phosphate phosphorus (InsP-P) in maize, wheat, barley and heat treated soybean meal, rapeseed meal and sunflower meal was determined by high-performance ion chromatography (HPIC). Approximately 0.88-0.96 of the InsP-P in the feedstuffs was present in the inositol hexaphosphate (InsP(6)) form, whereas the rest was in the inositol pentaphosphate (InsP(5)) form and for oilseeds a very small amount was present as inositol tetraphosphaie (InSP4). Rapeseed differed from this pattern by having as much as 300 and 609 InsP(4)-P/kg of the total InsP-P pool. The effect of pelleting (90 degrees C) and extrusion cooking (130-140 degrees C, 6.5 MPa) or. the composition of lnsP-P was investigated. Neither treatment had any major effect on the total content of InsP-P in the feedstuffs. However, as indicated by the statistically significant effects on the proportion of the inositol phosphates, extrusion cooking shifted the inositol phosphates from InsP(6)-P towards InSP5-P both in cereals (P=0.002) and in oilseeds (P
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| 24. |
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| 25. |
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| 26. |
- Sandberg, Dan T, et al.
(författare)
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Intra-image referencing for simplified assessment of HER2-expression in breast cancer metastases using the Affibody molecule ABY-025 with PET and SPECT.
- 2017
-
Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 44:8, s. 1337-1346
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: In phase I/II-studies radiolabelled ABY-025 Affibody molecules identified human epidermal growth factor receptor 2 (HER2) expression in breast cancer metastases using PET and SPECT imaging. Here, we wanted to investigate the utility of a simple intra-image normalization using tumour-to-reference tissue-ratio (T/R) as a HER2 status discrimination strategy to overcome potential issues related to cross-calibration of scanning devices.METHODS: Twenty-three women with pre-diagnosed HER2-positive/negative metastasized breast cancer were scanned with [(111)In]-ABY-025 SPECT/CT (n = 7) or [(68)Ga]-ABY-025 PET/CT (n = 16). Uptake was measured in all metastases and in normal spleen, lung, liver, muscle, and blood pool. Normal tissue uptake variation and T/R-ratios were established for various time points and for two different doses of injected peptide from a total of 94 whole-body image acquisitions. Immunohistochemistry (IHC) was used to verify HER2 expression in 28 biopsied metastases. T/R-ratios were compared to IHC findings to establish the best reference tissue for each modality and each imaging time-point. The impact of shed HER2 in serum was investigated.RESULTS: Spleen was the best reference tissue across modalities, followed by blood pool and lung. Spleen-T/R was highly correlated to PET SUV in metastases after 2 h (r = 0.96, P < 0.001) and reached an accuracy of 100% for discriminating IHC HER2-positive and negative metastases at 4 h (PET) and 24 h (SPECT) after injection. In a single case, shed HER2 resulted in intense tracer retention in blood. In the remaining patients shed HER2 was elevated, but without significant impact on ABY-025 biodistribution.CONCLUSION: T/R-ratios using spleen as reference tissue accurately quantify HER2 expression with radiolabelled ABY-025 imaging in breast cancer metastases with SPECT and PET. Tracer binding to shed HER2 in serum might affect quantification in the extreme case.
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| 27. |
- Sandberg, Henrik, et al.
(författare)
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Differentially private state estimation in distribution networks with smart meters
- 2015
-
Ingår i: Proceedings of the IEEE Conference on Decision and Control. - : IEEE conference proceedings. - 9781479978861 ; , s. 4492-4498
-
Konferensbidrag (refereegranskat)abstract
- State estimation is routinely being performed in high-voltage power transmission grids in order to assist in operation and to detect faulty equipment. In low- and medium-voltage power distribution grids, on the other hand, few real-time measurements are traditionally available, and operation is often conducted based on predicted and historical data. Today, in many parts of the world, smart meters have been deployed at many customers, and their measurements could in principle be shared with the operators in real time to enable improved state estimation. However, customers may feel reluctance in doing so due to privacy concerns. We therefore propose state estimation schemes for a distribution grid model, which ensure differential privacy to the customers. In particular, the state estimation schemes optimize different performance criteria, and a trade-off between a lower bound on the estimation performance versus the customers' differential privacy is derived. The proposed framework is general enough to be applicable also to other distribution networks, such as water networks.
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| 28. |
- Sandberg, Jan
(författare)
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Corrosion-induced release of zinc and copper in marine environments
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This licentiate study was initiated by copper, zinc and galvanized steel producers in Europe, who felt a need to assess runoff rates of copper and zinc from the pure metals and commercial products at marine exposure conditions. Their motive was the increasing concern in various European countries and the on-going risk assessments of copper and zinc within the European commission. Also the circumstance that available runoff rates so far, had been reported for mainly urban exposure conditions, rather than marine. A collaboration was therefore established with the French Corrosion Institute, which runs a marine test site in Brest, and a set of vital questions were formulated. Their answers are the essence of this licentiate study. Based on the ISO corrosivity classification and one-year exposures, the marine atmosphere of Brest is fairly corrosive for zinc (class C3) and highly corrosive for copper (C4). Despite higher corrosivity classifications for both metals in Brest compared to the urban site of Stockholm, used as a reference site, nearly all runoff rates assessed for copper, zinc and their commercial products were lower in Brest compared to Stockholm. This was attributed to a higher surface wetting in Brest and concomitant higher removal rate of deposited chloride and sulphate species from the marine-exposed surfaces. The comparison shows that measured corrosion rates cannot be used to predict runoff rates, since different physicochemical processes govern corrosion and runoff respectively. For copper, the runoff rate in Brest was approximately 1.1 g m-2 yr-1 with cuprite (Cu2O) as main patina constituent. During periods of very high chloride and sulphate deposition, paratacamite (Cu2Cl(OH)3) formed which increased the runoff rate to 1.5 g m-2 yr-1. For zinc, with hydrozincite (Zn5(CO3)2(OH)6) as the main patina constituent, the runoff rate was relatively stable at 2.6 g m-2 yr-1 throughout the year, despite episodes of heavy chloride and sulphate deposition. The application of organic coatings of varying thickness on artificially patinated copper or on different zinc-based products resulted in improved barrier properties and reduced runoff rates that seem highly dependent on thickness. The thickest organic coating (150 µm thick), applied on hot dipped galvanized steel, reduced the runoff rate by a factor of 100. No deterioration of organic coatings was observed during the one-year exposures. Alloying zinc-based products with aluminium resulted in surface areas enriched in aluminium and concomitant reduced zinc runoff rates. The release rate and bioavailability of copper from different anti-fouling paints into artificial seawater was also investigated. It turned out that the release rate not only depends on the copper concentration in the paint, but also on paint matrix properties and other released metal constituents detected. Far from all copper was bioavailabe at the immediate release situation. In all, the results suggest the importance of assessing the ecotoxic response of anti-fouling paints not only by regarding the copper release, but rather through an integrated effect of all matrix constituents.
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| 29. |
- Sandberg, Sofia, 1976, et al.
(författare)
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Low anterior resection syndrome in a Scandinavian population of patients with rectal cancer: a longitudinal follow-up within the QoLiRECT study
- 2020
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Ingår i: Colorectal Disease. - : Wiley. - 1462-8910 .- 1463-1318. ; 22:10, s. 1367-1378
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: Low anterior resection syndrome (LARS) is common after low anterior resection. Our aim was to evaluate the prevalence and ‘bother’ (subjective, symptom-associated distress) of major LARS after 1 and 2years, identify possible risk factors and relate the bowel function to a reference population. Method: The QoLiRECT (Quality of Life in RECTal cancer) study is a Scandinavian prospective multicentre study including 1248 patients with rectal cancer, of whom 552 had an anterior resection. Patient questionnaires were distributed at diagnosis and after 1, 2 and 5years. Data from the baseline and at 1- and 2-year follow-up were included in this study. Results: The LARS score was calculated for 309 patients at 1year and 334 patients at 2years. Prevalence was assessed by a generalized linear mixed effects model. Major LARS was found in 63% at 1year and 56% at 2years. Bother was evident in 55% at 1year, decreasing to 46% at 2years. Major LARS was most common among younger women (69%). Among younger patients, only marginal improvement was seen over time (63–59%), for older patients there was more improvement (62–52%). In the reference population, the highest prevalence of major LARS-like symptoms was noted in older women (12%). Preoperative radiotherapy, defunctioning stoma and tumour height were found to be associated with major LARS. Conclusion: Major LARS is common and possibly persistent over time. Younger patients, especially women, are more affected, and perhaps these patients should be prioritized for early stoma closure to improve the chance of a more normal bowel function.
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| 30. |
- Sandberg, Sofia, 1976, et al.
(författare)
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Predicting life with a permanent end colostomy: A prospective study on function, bother and acceptance
- 2021
-
Ingår i: Colorectal Disease. - : Wiley. - 1462-8910 .- 1463-1318. ; 23:10, s. 2681-2689
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: The factors that influence a patient's experience of a colostomy are not known. The aim of this study was to characterise stoma function, stoma-related bother and acceptance among patients operated for rectal cancer and to investigate if there were any preoperative personal factors with predictive impact on long-term stoma-related bother. Methods: The QoLiRECT (Quality of Life in RECTal cancer) study is a prospective multicentre study of patients with rectal cancer. This was a subgroup analysis of patients with a permanent colostomy with a 2-year follow-up. Penalised regression models with shrinkage estimation were used to predict the 1-and 2-year bother using baseline data. The predictive value and the importance of the included variables were evaluated using bootstrap resampling techniques. Results: A total of 379 patients were included. Overall stoma acceptance was high and a majority of patients were not bothered by their stoma; 77% and 83% at 1 and 2years, respectively. The subgroup of patients with stoma-related bother had a high prevalence of difficulties, especially fear of leakage, and a low stoma acceptance in daily life. Both clinical and personal factors were associated with stoma-related bother. The most important factors were quality of life and physical health, but the prediction accuracy was low. Conclusions: Stoma-related bother was associated with overall stoma dysfunction. As stoma-related bother is a multifactorial problem, it was not possible to predict which patients will experience stoma-related bother. It is therefore of importance to prevent stoma-related symptoms and optimise stoma function to reduce long-term bother and increase stoma acceptance.
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| 31. |
- Sandström, Mattias, et al.
(författare)
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Biodistribution and Radiation Dosimetry of the Anti-HER2 Affibody Molecule Ga-68-ABY-025 in Breast Cancer Patients
- 2016
-
Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 57:6, s. 867-871
-
Tidskriftsartikel (refereegranskat)abstract
- Ga-68-ABY-025 is a radiolabeled Affibody molecule for in vivo diagnosis of human epidermal growth factor receptor 2 (HER2)-positive breast cancer tumors with PET. The aim of the present work was to measure the biodistribution and estimate the radiation dosimetry of Ga-68-ABY-025 for 2 different peptide mass doses in a single group of patients using dynamic and serial whole-body PET/CT. Methods: Eight patients with metastatic breast cancer were included. Each patient underwent an abdominal 45-min dynamic and 3 whole-body PET/CT scans at 1, 2, and 4 h after injection of a low peptide dose (LD) and a high peptide dose (HD), with approximately the same amount of radioactivity, in separate investigations 1 wk apart. As input to the absorbed dose calculations, volumes of interest were drawn on all clearly identifiable source organs: liver, kidneys, spleen, descending aorta, and upper large intestine. Absorbed doses were calculated using OLINDA/EXM, version 1.1. Results: Of the major organs, the highest radionuclide uptake at 1, 2, and 4 h after injection was observed in the kidneys and liver. The highest absorbed organ doses were seen in the kidneys, followed by the liver for both LD and HD Ga-68-ABY-025. Absorbed doses to liver and kidneys were slightly but significantly higher for LD. Total effective dose was 0.030 +/- 0.003 mSv/MBq for LD and 0.028 +/- 0.002 mSv/MBq for HD. Conclusion: The effective dose for a typical 200-MBq administration of Ga-68-ABY-025 is 6.0 mSv for LD and 5.6 mSv for HD. Therefore, from a radiation dosimetry point of view, HD is preferred for PET/CT evaluation of HER2-expressing breast cancer tumors. These effective doses are somewhat higher than earlier published values for other Ga-68-labeled tracers, such as 0.021 +/- 0.003 mSv/MBq for Ga-68-DOTATATE and Ga-68-DOTATOC, mainly because of higher uptake in liver and kidney.
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| 32. |
- Santas, Serkan, et al.
(författare)
-
Continuous authentication security games
- 2021
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Ingår i: Game Theory and Machine Learning for Cyber Security. - : Wiley. ; , s. 180-203
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 33. |
- Saritas, Serkan, et al.
(författare)
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Adversarial Attacks on CFO-Based Continuous Physical Layer Authentication : A Game Theoretic Study
- 2021
-
Ingår i: ICC 2021 - IEEE International Conference on Communications. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- 5G and beyond 5G low power wireless networks make Internet of Things (IoT) and Cyber-Physical Systems (CPS) applications capable of serving massive amounts of devices and machines. Due to the broadcast nature of wireless networks, it is crucial to secure the communication between these devices and machines from spoofing and interception attacks. This paper is concerned with the security of carrier frequency offset (CFO) based continuous physical layer authentication. The interaction between an attacker and a defender is modeled as a dynamic discrete leader-follower game with imperfect information. In the considered model, a legitimate user (Alice) communicates with the defender/operator (Bob) and is authorized by her CFO continuously. The attacker (Eve), by listening/eavesdropping the communication between Alice and Bob, tries to learn the CFO characteristics of Alice and aims to inject malicious packets to Bob by impersonating Alice. First, by showing that the optimal attacker strategy is a threshold policy, an optimization problem of the attacker with exponentially growing action space is reduced to a tractable integer optimization problem with a single parameter, then the corresponding defender cost is derived. Extensive simulations illustrate the characteristics of optimal strategies/utilities of the players depending on the actions, and show that the defender's optimal false positive rate causes attack success probabilities to be in the order of 0.99. The results show the importance of the parameters while finding the balance between system security and efficiency.
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| 34. |
- Saritas, Serkan, et al.
(författare)
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Adversarial Attacks on Continuous Authentication Security: A Dynamic Game Approach
- 2019
-
Ingår i: 10th International Conference, GameSec 2019, Stockholm, Sweden, October 30 – November 1, 2019, Proceedings. - Cham : Springer International Publishing. ; , s. 439-458
-
Konferensbidrag (refereegranskat)abstract
- Identity theft through phishing and session hijacking attacks has become a major attack vector in recent years, and is expected to become more frequent due to the pervasive use of mobile devices. Continuous authentication based on the characterization of user behavior, both in terms of user interaction patterns and usage patterns, is emerging as an effective solution for mitigating identity theft, and could become an important component of defense-in-depth strategies in cyber-physical systems as well. In this paper, the interaction between an attacker and an operator using continuous authentication is modeled as a stochastic game. In the model, the attacker observes and learns the behavioral patterns of an authorized user whom it aims at impersonating, whereas the operator designs the security measures to detect suspicious behavior and to prevent unauthorized access while minimizing the monitoring expenses. It is shown that the optimal attacker strategy exhibits a threshold structure, and consists of observing the user behavior to collect information at the beginning, and then attacking (rather than observing) after gathering enough data. From the operator’s side, the optimal design of the security measures is provided. Numerical results are used to illustrate the intrinsic trade-off between monitoring cost and security risk, and show that continuous authentication can be effective in minimizing security risk.
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| 35. |
- Saritas, Serkan, et al.
(författare)
-
Passive Fault-tolerant Estimation under Strategic Adversarial Bias
- 2020
-
Ingår i: 2020 American Control Conference (ACC). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 4644-4651
-
Konferensbidrag (refereegranskat)abstract
- This paper is concerned with the problem of fault-tolerant estimation in cyber-physical systems. In cyber-physical systems, such as critical infrastructures, networked embedded sensors are widely used for monitoring and can be exploited by an adversary to deceive the control center by modifying measured values. The deception is modeled as a bias; i.e., there is a misalignment between the objective functions of the control center and the adversarial sensor. Different from previous studies, a Stackelberg equilibrium of a cheap talk setup is adapted to the attacker-defender game setting for the first time. That is, the defender (control center), as a receiver, is the leader, and the attacker (adversarial sensor), as a transmitter, is the follower. The equilibrium strategies and the associated costs are characterized for uniformly distributed variables and quadratic objective functions, and an analysis on the uniqueness of the equilibrium is provided. It is shown that the attacker and defender costs at the equilibrium are increasing with the bias and decreasing with the number of quantization levels. Our results surprisingly show that, under certain conditions, the attacker prefers a public bias rather than a private one.
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| 36. |
- Sasahara, Hampei, et al.
(författare)
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Green Routing Game : Strategic Logistical Planning using Mixed Fleets of ICEVs and EVs
- 2022
-
Ingår i: 2022 IEEE 61ST CONFERENCE ON DECISION AND CONTROL (CDC). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 6358-6363
-
Konferensbidrag (refereegranskat)abstract
- This paper introduces a "green" routing game between multiple logistic operators (players), each owning a mixed fleet of internal combustion engine vehicle (ICEV) and electric vehicle (EV) trucks. Each player faces the cost of delayed delivery (due to charging requirements of EVs) and a pollution cost levied on the ICEVs. This cost structure models: 1) limited battery capacity of EVs and their charging requirement; 2) shared nature of charging facilities; 3) pollution cost levied by regulatory agency on the use of ICEVs. We characterize Nash equilibria of this game and derive a condition for its uniqueness. We also use the gradient projection method to compute this equilibrium in a distributed manner. Our equilibrium analysis is useful to analyze the trade-off faced by players in incurring higher delay due to congestion at charging locations when the share of EVs increases versus a higher pollution cost when the share of ICEVs increases. A numerical example suggests that to increase marginal pollution cost can reduce inefficiency of equilibria.
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| 37. |
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| 38. |
- Sörensen, Jens, et al.
(författare)
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First-in-Human Molecular Imaging of HER2 Expression in Breast Cancer Metastases Using the In-111-ABY-025 Affibody Molecule
- 2014
-
Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 55:5, s. 730-735
-
Tidskriftsartikel (refereegranskat)abstract
- The expression status of human epidermal growth factor receptor type 2 (HER2) predicts the response of HER2-targeted therapy in breast cancer. ABY-025 is a small reengineered Affibody molecule targeting a unique epitope of the HER2 receptor, not occupied by current therapeutic agents. This study evaluated the distribution, safety, dosimetry, and efficacy of In-111-ABY-025 for determining the HER2 status in metastatic breast cancer. Methods: Seven patients with metastatic breast cancer and HER2-positive (n = 5) or - negative (n 5 2) primary tumors received an intravenous injection of approximately 100 mu g (similar to 140 MBq) of In-111-ABY-025. Planar gamma-camera imaging was performed after 30 min, followed by SPECT/CT after 4, 24, and 48 h. Blood levels of radioactivity, antibodies, shed serum HER2, and toxicity markers were evaluated. Lesional HER2 status was verified by biopsies. The metastases were located by F-18-FDG PET/CT 5 d before In-111-ABY-025 imaging. Results: Injection of In-111-ABY-025 yielded a mean effective dose of 0.15 mSv/MBq and was safe, well tolerated, and without drug-related adverse events. Fast blood clearance allowed high-contrast HER2 images within 4-24 h. No anti-ABY025 antibodies were observed. When metastatic uptake at 24 h was normalized to uptake at 4 h, the ratio increased in HER2-positive metastases and decreased in negative ones (P, < 0.05), with no overlap and confirmation by biopsies. In 1 patient, with HER2- positive primary tumor, In-111-ABY-025 imaging correctly suggested a HER2negative status of the metastases. The highest normal-tissue uptake was in the kidneys, followed by the liver and spleen. Conclusion: In-111-ABY- 025 appears safe for use in humans and is a promising noninvasive tool for discriminating HER2 status in metastatic breast cancer, regardless of ongoing HER2-targeted antibody treatment.
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| 39. |
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| 40. |
- Sörensen, Jens, et al.
(författare)
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Measuring HER2-Receptor Expression In Metastatic Breast Cancer Using [(68)Ga]ABY-025 Affibody PET/CT
- 2016
-
Ingår i: Theranostics. - : Ivyspring International Publisher. - 1838-7640. ; 6:2, s. 262-271
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Positron Emission Tomography (PET) imaging of HER2 expression could potentially be used to select patients for HER2-targed therapy, predict response based on uptake and be used for monitoring. In this phase I/II study the HER2-binding Affibody molecule ABY-025 was labeled with (68)Ga-gallium ([(68)Ga]ABY-025) for PET to study effect of peptide mass, test-retest variability and correlation of quantified uptake in tumors to histopathology.EXPERIMENTAL DESIGN: Sixteen women with known metastatic breast cancer and on-going treatment were included and underwent FDG PET/CT to identify viable metastases. After iv injection of 212±46 MBq [(68)Ga]ABY-025 whole-body PET was performed at 1, 2 and 4 h. In the first 10 patients (6 with HER2-positive and 4 with HER2-negative primary tumors), [(68)Ga]ABY-025 PET/CT with two different doses of injected peptide was performed one week apart. In the last six patients (5 HER2-positive and 1 HER2-negative primary tumors), repeated [(68)Ga]ABY-025 PET were performed one week apart as a test-retest of uptake in individual lesions. Biopsies from 16 metastases in 12 patients were collected for verification of HER2 expression by immunohistochemistry and in-situ hybridization.RESULTS: Imaging 4h after injection with high peptide content discriminated HER2-positive metastases best (p<0.01). PET SUV correlated with biopsy HER2-scores (r=0.91, p<0.001). Uptake was five times higher in HER2-positive than in HER2-negative lesions with no overlap (p=0.005). The test-retest intra-class correlation was r=0.996. [(68)Ga]ABY-025 PET correctly identified conversion and mixed expression of HER2 and targeted treatment was changed in 3 of the 16 patients.CONCLUSION: [(68)Ga]ABY-025 PET accurately quantifies whole-body HER2-receptor status in metastatic breast cancer.
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| 41. |
- Tafti, Abbas, et al.
(författare)
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Towards understanding disruption in the market for professional services in construction
- 2022
-
Ingår i: SBEfin2022 Emerging Concepts for Sustainable Built Environment (SBEfin2022). - : Institute of Physics (IOP).
-
Konferensbidrag (refereegranskat)abstract
- The challenges faced by professional service companies in construction are increasing simultaneously as enablers such as digitalization and industrialization are developing. Currently, there are indications of two main diverging market trends: Productification and Servicification. This paper hypothesises that these two trends can be classified as Asset-dominant logic. In construction, the digital development, is currently regularly decoupled from the business model development. In support of business model innovation, this paper's aim is to how we can understand and articulate the development of the markets for professional services in construction by describing concepts for understanding and analysing design work in the context of asset-dominant logic, as opposed to the current dominating Resource-dominated logic. The result indicates that productificiation, includes industrialization (product-based approach) by considering applying disruptive technologies, with the aid of a platform and in an ecosystem, making it possible to create value for the customer by taking service-dominant logic into account. Finally, the paper concludes with an attempt to demonstrate the mechanism of market development by considering the asset-dominant logic as a backdrop to the business model innovations that asset-dominant consulting will start to undertake in the coming months and years.
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| 42. |
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| 43. |
- Teixeira, André, et al.
(författare)
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Optimal Power Flow : Closing the Loop over Corrupted Data
- 2012
-
Ingår i: 2012 American Control Conference (ACC). - : IEEE Computer Society. - 9781467321020 ; , s. 3534-3540
-
Konferensbidrag (refereegranskat)abstract
- Recently the power system state estimator was shown to be vulnerable to malicious deception attacks on the measurements, resulting in biased estimates. In this work we analyze the behavior of the Optimal Power Flow (OPF) algorithm in the presence of such maliciously biased estimates and the resulting consequences to the system operator. In particular, we characterize the set of attacks that may lead the operator to apply the erroneous OPF recommendation. Such characterization is used to improve a previously proposed security index by also considering the attack impact, which may be used for allocation and prioritization of protective measures. Additionally, we propose an analytical expression for the optimal solution of a simplified OPF problem with corrupted measurements. A small analytical example is discussed to illustrate and motivate our contributions.
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| 44. |
- Teixeira, André, et al.
(författare)
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Security of smart distribution grids : Data integrity attacks on integrated volt/VAR control and countermeasures
- 2014
-
Ingår i: American Control Conference (ACC), 2014. - : IEEE conference proceedings. - 9781479932726 ; , s. 4372-4378, s. 4372-4378
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Konferensbidrag (refereegranskat)abstract
- We examine the feasibility of an attack on themeasurements that will be used by integrated volt-var control(VVC) in future smart power distribution systems. The analysisis performed under a variety of assumptions of adversarycapability regarding knowledge of details of the VVC algorithmused, system topology, access to actual measurements, andability to corrupt measurements. The adversary also faces anoptimization problem, which is to maximize adverse impactwhile remaining stealthy. This is achieved by first identifyingsets of measurements that can be jointly but stealthily corrupted.Then, the maximal impact of such data corruptionis computed for the case where the operator is unaware ofthe attack and directly applies the configuration from theintegrated VVC. Furthermore, since the attacker is constrainedto remaining stealthy, we consider a game-theoretic frameworkwhere the operator chooses settings to maximize observabilityand constrain the adversary action space.
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| 45. |
- Thobaben, Ragnar, et al.
(författare)
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Wiretap Codes for Secure Multi-Party Computation
- 2014
-
Ingår i: Globecom Workshops (GC Wkshps), 2014. - : IEEE conference proceedings.
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we propose a new secret sharing scheme for secure multi-party computation. We present a general framework that allows us to construct efficient secret sharing schemes from channel coding techniques for the wiretap channel. The resulting schemes can be employed to securely calculate linear functions of data that are distributed in a network without leaking any information on the data except the desired result. For the examples considered in this paper, our schemes minimize the communication overhead while keeping the data perfectly secure. Compared to conventional schemes, for which the communication overhead grows quadratically in the number of clients in the considered scenarios, the communication overhead for our approach grows only linearly with the number of clients. This property is maintained even if our secret sharing scheme is set up to introduce redundancy in order to compensate for losses of secret shares. While we only consider the case of passive eavesdroppers and implementations based on nested Reed-Solomon codes in this paper, the proposed framework can also be applied in other cases (e.g., when clients tamper with the data) by taking into account the effects of attacks in the design of the underlying wiretap code.
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| 46. |
- Vuković, Ognjen, et al.
(författare)
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Network-Aware Mitigation of Data Integrity Attacks on Power System State Estimation
- 2012
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Ingår i: IEEE Journal on Selected Areas in Communications. - 0733-8716 .- 1558-0008. ; 30:6, s. 1108-1118
-
Tidskriftsartikel (refereegranskat)abstract
- Critical power system applications like contingency analysis and optimal power flow calculation rely on the power system state estimator. Hence the security of the state estimator is essential for the proper operation of the power system. In the future more applications are expected to rely on it, so that its importance will increase. Based on realistic models of the communication infrastructure used to deliver measurement data from the substations to the state estimator, in this paper we investigate the vulnerability of the power system state estimator to attacks performed against the communication infrastructure. We define security metrics that quantify the importance of individual substations and the cost of attacking individual measurements. We propose approximations of these metrics, that are based on the communication network topology only, and we compare them to the exact metrics. We provide efficient algorithms to calculate the security metrics. We use the metrics to show how various network layer and application layer mitigation strategies, like single and multi-path routing and data authentication, can be used to decrease the vulnerability of the state estimator. We illustrate the efficiency of the algorithms on the IEEE 118 and 300 bus benchmark power systems.
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| 47. |
- Vuković, Ognjen, et al.
(författare)
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Network-layer protection schemes against stealth attacks on state estimators in power systems
- 2011
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Ingår i: IEEE SmartGridComm 2011. - : IEEE. - 9781457717024
-
Konferensbidrag (refereegranskat)abstract
- The power system state estimator is an important application used to calculate optimal power flows, to maintain the system in a secure state, and to detect faulty equipment. Its importance in the operation of the smart grid is expected to increase, and therefore its security is an important concern. Based on a realistic model of the communication infrastructure used to deliver measurement data from the substations to the state estimator, in this paper we investigate the vulnerability of the power system state estimator to attacks performed against the communication infrastructure. We define security metrics that quantify the importance of individual substations and the cost of attacking individual measurements. We provide efficient algorithms to calculate these metrics, and use the metrics to show how various network layer and application layer mitigation strategies can be used to decrease the vulnerability of the state estimator. We illustrate the efficiency of the algorithms on the IEEE 118 and 300 bus benchmark power systems.
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| 48. |
- Wang, Xiaoyang, 1965, et al.
(författare)
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X-linked inhibitor of apoptosis (XIAP) protein protects against caspase activation and tissue loss after neonatal hypoxia-ischemia
- 2004
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Ingår i: Neurobiol Dis. - Univ Gothenburg, Dept Physiol, Perinatal Ctr, SE-40530 Gothenburg, Sweden. Zhengzhou Univ, Affiliated Hosp 3, Dept Pediat, Zhengzhou 450052, Peoples R China. Univ Gothenburg, Sahlgrens Univ Hosp, Dept Obstet & Gynecol, SE-41685 Gothenburg, Sweden. Uppsala Univ, Dept Neurosci, SE-75123 Uppsala, Sweden. Univ Gothenburg, Dept Med Biophys, SE-40530 Gothenburg, Sweden. Univ Gothenburg, Queen Silvia Childrens Hosp, Dept Pediat, SE-41685 Gothenburg, Sweden. : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0969-9961 .- 1095-953X. ; 16:1, s. 179-89
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Tidskriftsartikel (refereegranskat)abstract
- Nine-day-old transgenic XIAP overexpressing (TG-XIAP) and wild-type mice were subjected to left carotid artery ligation and 10% O(2) for 60 min, leading to widespread infarctions in the ipsilateral hemisphere during reperfusion. The activation of caspase-3 and -9 seen in wild-type animals was virtually abolished in TG-XIAP mice. Tissue loss was significantly reduced from 54.4 +/- 4.1 mm(3) (mean +/- SEM) in wild-type mice to 33.1 +/- 2.1 mm(3) in the TG-XIAP mice. Injured neurons displayed stronger XIAP staining during reperfusion, particularly in the nuclei. XIAP was colocalized with XAF-1, Smac, and HtrA2 in injured neurons after hypoxia-ischemia (HI). XIAP was cleaved after HI, and Smac immunoprecipitation co-precipitated a 25-kDa C-terminal fragment of XIAP, indicating that Smac preferentially bound to cleaved XIAP. These findings provide the first evidence that increased XIAP levels protect the neonatal brain against HI.
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