| 1. |
- Andersson, Per-Åke, 1945-
(författare)
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Multi-year maintenance optimisation for paved public roads - segment based modelling and price-directive decomposition
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- I avhandlingen studeras hur kostnadseffektiva underhålls- (uh-)planer för belagd väg kan genereras, på basis av information om aktuellt vägytetillstånd och funktionella modeller för kostnads- och tillståndsförändringar, delvis utvecklade i samarbete med svenska Vägverket (VV). Tilltänkt användning är på strategisk och programnivå, innan mer detaljerad objektinformation finns att tillgå. Till skillnad från hittills använda modeller, så genereras individuella uh-planer för varje vägsegment (en homogen vägsträcka vad gäller aktuellt beläggningstillstånd och beläggningshistorik), i kontinuerliga tillstånds- och åtgärdsrum. Genom användning av Lagrangerelaxerande optimeringsteknik, så kan de speciella nytto/kostnads-kvot-villkor som VV ålägger varje uh-objekt naturligen hanteras med dualpriser för budgetvillkoren. Antalet vägsegment som konkurrerar om budgetmedlen är vanligtvis stort. Data från VV:s Vägdatabank för Värmland har använts, omfattande ca 9000 vägsegment. Genom den stora datamängden har datorprogrammen implementerats för parallellbearbetning. Under avhandlingsarbetet har projektet beviljats tillgång till Monolith PCklustret vid NSC. För att kunna reducera optimeringskörtiderna har modell- och metodutveckling varit nödvändig. Genom att aggregera vägsegmenten till vägklasser har goda startvärden på dualpriserna erhållits. Genom utvecklingen av en speciell restvärdesrutin har den explicit behandlade tidsperioden kunnat reduceras. Vid lösandet av det duala subproblemet har speciell uppmärksamhet ägnats åt de diskretiseringseffekter som uppstår i metoden dynamisk programmering. En typ av tillämpning avser ett delvägnät, exempelvis en väg. Valideringsstudier har genomförts på väg 63 i Värmland – med lovande men inte tillfredsställande resultat (se nedan). En speciell modell för samordnat uh beaktar stordriftsfördelarna vid samtidig åtgärd på en hel vägsträcka. Den andra huvudtypen av studier gäller ett helt nätverk. Flera metodtyper har tillämpats, både för att lösa de relaxerade optimeringsproblemen och för att generera uhplaner som uppfyller budgetvillkoren. För en anständig diskretisering är körtiderna för hela Värmland mindre än 80 CPU-timmar. Genom en a posteriori primal heuristik reduceras kraven på parallellbearbetning till ett litet PC-kluster. Avhandlingen studerar vidare effekterna av omfördelade budgetmedel samt en övergång till en transparent, stokastisk modell – vilka båda visar små avvikelser från basmodellen.Optimeringsresultaten för Värmland indikerar att budgetnivåer på ca 40% av Värmlands verkliga uh-budget är tillräckliga. Dock saknas viktiga kostnadsdrivande faktorer i denna första modellomgång, exempelvis vissa funktionella prestanda (säkerhet), all miljöpåverkande prestanda (buller etc.) och strukturell prestanda (ex.vis bärighet, som enbart modelleras via ett åldersmått). För ökad tilltro till PMS i allmänhet och optimering i synnerhet, bör avvikelserna analyseras ytterligare och leda till förbättringar vad gäller tillståndsmätning, tillståndseffekt- & kostnadsmodellering samt matematisk modellering & implementering.
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| 2. |
- Bourdieu, Pierre, et al.
(författare)
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Leve idrottspedagogiken : En vänbok tillägnad Lars-Magnus Engström
- 2005
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Vem ägnar sig åt idrott? Vilken betydelse har fritiden i barns och ungdomars liv? Vad innebär hälsa i skolämnet idrott och hälsa?Leve idrottspedagogiken! tillägnas Lars-Magnus Engström. Texterna i boken speglar delar av det idrottspedagogiska forskningsområdet i Sverige, vars framväxt Lars-Magnus Engström varit den främste företrädaren för. Läsaren får här ta del av exempelvis idrottskulturen, fritidskulturen och skolans ämne idrott och hälsa. Genomgående handlar texterna om villkoren för barns och ungdomars deltagane och om de olika lärprocesser som sker i anslutning till idrottsutövning.Lars-Magnus Engström har gjort betydande insatser som forskare och lärare samt som professor vid Lärarhögskolan i Stockholm och vid Gymnastik- och idrottshögskolan. I snart fyrtion år har han arbetat med studier kring påverkans- och lärprocesser i idrott. Hans forskning har främst kretsat kring människors idrottsvanor och vilka som utvecklar en fysiskt aktiv livsstil. Idrotts- och motionsutövningar ger både ett så kallat egenvärde och investeringsvärde. Med dessa begrepp bland många andra har Lars-Magnus Engström bidragit till en fördjupad vetenskaplig förståelse av idrottskulturen.De flesta författarna har eller har haft Lars-Magnus Engström som handledare och tillhör forskningsgruppen för pedagogik, idrott och fritidskultur. Redaktörer för boken är Karin Redelius och Håkan Larsson.
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| 3. |
- Brikell, Isabell, et al.
(författare)
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Relative Immaturity in Childhood and Attention-Deficit/Hyperactivity Disorder Symptoms From Childhood to Early Adulthood : Exploring Genetic and Environmental Overlap Across Development
- 2016
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier. - 0890-8567 .- 1527-5418. ; 55:10, s. 886-895
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Attention-deficit/hyperactivity disorder (ADHD) has been linked to immaturity relative to peers in childhood, yet it is unclear how such immaturity is associated with ADHD across development. This longitudinal twin study examined the genetic and environmental contributions to the association between parents' perception of their child's immaturity relative to peers (RI) in childhood and ADHD symptoms across development.Method: 1,302 twin pairs from the Swedish Twin Study of Child and Adolescent Development were followed prospectively from childhood to early adulthood. Parent ratings of RI were collected at 8 to 9 years and parent and self-ratings of ADHD symptoms were collected at 8 to 9, 13 to 14, 16 to 17, and 19 to 20 years using the Child Behavior Checklist Attention Problems scale. In addition, ADHD symptoms corresponding to DSM criteria were used for sensitivity analysis. Analyses were conducted using longitudinal structural equation modeling with multiple raters.Results: RI-related etiologic factors, predominantly influenced by genes, explained 10-14% of the variance in ADHD symptoms from 8 to 9 up to 16 to 17 years. The influence of these RI-related factors on ADHD symptoms attenuated to 4% by 19 to 20 years of age. The remaining variance in ADHD symptoms was primarily explained by genetic factors independent of RI, which remained relatively stable across development, explaining 19% to 30% of the variance in ADHD symptoms from 13 to 14 up to 19 to 20 years.Conclusion: The results show that RI is significantly associated with ADHD symptoms, particularly during childhood and adolescence, and that the association is primarily explained by a shared genetic liability. Nevertheless, the magnitude of associations across development was modest, highlighting that RI is merely one aspect contributing to the complex etiology of ADHD symptoms.
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| 4. |
- Larsson-Kråik, Per-Olof, et al.
(författare)
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Pressure fluctuations as grease soaps pass through an EHL contact
- 2000
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Ingår i: Tribology International. - 0301-679X .- 1879-2464. ; 33:3-4, s. 211-216
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Tidskriftsartikel (refereegranskat)abstract
- Soap lumps entering a grease-lubricated elastohydrodynamic lubrication (EHL) contact were traced as they passed through the contact by using optical interferometry in a standard Ball & Disc apparatus and a high-speed video camera with light enhancer. One specific soap lump could be traced when it was passing through the contact and sharp images of the passing lump could be captured. This paper presents a combined experimental and numerical approach to determine what is happening when such lumps pass through the contact. From the fringe pattern, obtained by optical interferometry, a film thickness map is created by using image processing. This is done for every time step (1 ms) as the lump is passing through the contact. These maps serve as input to a numerical computation of the pressure by assuming elastic deformation theory. Consequently, no assumptions about the rheological behaviour of the grease have to be made. Two greases were studied, based on the same synthetic poly-α-olefin but thickened with Li-12-OH and Li-complex respectively. It is seen that the soap thickened lumps can cause deep elastic indentations accompanied by large pressure fluctuations. The pressure level will in some cases be more than doubled due to lumps entering the contact region. The effects on noise level and operational life are also discussed.
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| 5. |
- Lenz, Annika, et al.
(författare)
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ZnO Nanoparticles Functionalized with Organic Acids: An Experimental and Quantum-Chemical Study
- 2009
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 113:40, s. 17332-17341
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical synthesis and physical characterization of ZnO nanoparticles functionalized with four different organic acids, three aromatic (benzoic, nicotinic, and trans-cinnamic acid) and one nonaromatic (formic acid), are reported. The functionalized nanoparticles have been characterized by X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV−vis, and photoluminescence spectroscopy. The adsorption of the organic acids at ZnO nanoparticles was further analyzed and interpreted using quantum-chemical density-functional theory computations. Successful functionalization of the nanoparticles was confirmed experimentally by the measured splitting of the carboxylic group stretching vibrations as well as by the N(1s) and C(1s) peaks from XPS. From a comparison between computed and experimental IR spectra, a bridging mode adsorption geometry was inferred. PL spectra exhibited a remarkably stronger near band edge emission for nanoparticles functionalized with formic acid as compared to the larger aromatic acids. From the quantum-chemical computations, this was interpreted to be due to the absence of aromatic adsorbate or surface states in the band gap of ZnO, caused by the formation of a complete monolayer of HCOOH. In the UV−vis spectra, strong charge-transfer transitions were observed.
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| 6. |
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| 7. |
- Daskalakis, Kosmas, et al.
(författare)
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Ex vivo activity of cytotoxic drugs and targeted agents in Small Intestinal NETs
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Small Intestinal Neuroendocrine Tumours (SI-NET) are considered to be generally resistant to systemic treatment. To date predictive markers for drug activity are lacking.Patients and Methods: Tumour samples from 27 patients with SI-NET were analyzed ex vivo for sensitivity to a panel of cytotoxic drugs and targeted agents using a short-term total cell kill assay. Samples of renal cancer, colorectal cancer (CRC), ovarian cancer, and chronic lymphocytic leukemia (CLL) were included for comparison. For the SI-NET subset, drug sensitivity was analyzed in relation to clinico-pathological variables and pre-treatment biomarkers.Results: For standard cytotoxic drugs, SI-NETs demonstrated similar or higher sensitivity to 5-FU, platinums, gemcitabine and doxorubicin compared with CRC. For targeted kinase inhibitors, SI-NET was among the most sensitive diagnoses. CLL and ovarian cancer were generally the most sensitive diagnoses to both cytotoxic drugs and protein kinase inhibitors. The mTOR inhibitor sirolimus exhibited modest cytotoxic activity.Individual SI-NET samples demonstrated great variability in ex vivo sensitivity for most drugs. Cross-resistance between different drugs also varied considerably, being higher among protein kinase inhibitors.Age, stage, grade, peritoneal carcinomatosis and extra-abdominal metastases as well as serum chromogranin A and urine 5-HIAA concentrations at diagnosis did not correlate to drug sensitivity ex vivo.Conclusions: SI-NETs exhibit variable but generally intermediate sensitivity ex vivo to cytotoxic and targeted drugs. Clinico-pathological factors and currently used biomarkers were not clearly associated to ex vivo sensitivity, challenging these criteria for treatment decisions in SI-NETs. The great variability in drug sensitivity calls for individualized selection of therapy.
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| 8. |
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| 9. |
- Daskalakis, Kosmas, et al.
(författare)
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Ex vivo activity of cytotoxic drugs and targeted agents in small intestinal neuroendocrine tumors
- 2018
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Ingår i: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 25:4, s. 471-480
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Tidskriftsartikel (refereegranskat)abstract
- Small intestinal neuroendocrine tumors (SI-NETs) are generally considered resistant to systemic treatment. To date, predictive markers for drug activity are lacking. Tumor samples from 27 patients with SI-NETs were analyzed ex vivo for sensitivity to a panel of cytotoxic drugs and targeted agents using a short-term total cell kill assay. Samples of renal cancer, colorectal cancer (CRC), ovarian cancer and chronic lymphocytic leukemia (CLL) were included for comparison. For the SI-NET subset, drug sensitivity was analyzed in relation to clinicopathological variables and pre-treatment biomarkers. For cytotoxic drugs, SI-NETs demonstrated similar or higher sensitivity to 5-FU, platinum, gemcitabine and doxorubicin compared with CRC. For several of the targeted kinase inhibitors, SI-NET was among the most sensitive solid tumor types. CLL and ovarian cancer were generally the most sensitive tumor types to both cytotoxic drugs and protein kinase inhibitors. SI-NET was more sensitive to the mTOR inhibitor sirolimus than the other solid tumor types tested. Individual SI-NET samples demonstrated great variability in ex vivo sensitivity for most drugs. Cross-resistance between different drugs also varied considerably, being higher among protein kinase inhibitors. Age, stage, grade, peritoneal carcinomatosis and extra-abdominal metastases as well as serum chromogranin A and urine 5-HIAA concentrations at diagnosis did not correlate to drug sensitivity ex vivo. SI-NETs exhibit intermediate sensitivity ex vivo to cytotoxic and targeted drugs. Clinicopathological factors and currently used biomarkers are not clearly associated to ex vivo sensitivity, challenging these criteria for treatment decisions in SI-NET. The great variability in drug sensitivity calls for individualized selection of therapy.
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| 10. |
- Engström, Gunnar, et al.
(författare)
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Pulmonary function and atherosclerosis in the general population : causal associations and clinical implications
- 2024
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Ingår i: European Journal of Epidemiology. - : Springer Nature. - 0393-2990 .- 1573-7284. ; 39:1, s. 35-49
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Tidskriftsartikel (refereegranskat)abstract
- Reduced lung function is associated with cardiovascular mortality, but the relationships with atherosclerosis are unclear. The population-based Swedish CArdioPulmonary BioImage study measured lung function, emphysema, coronary CT angiography, coronary calcium, carotid plaques and ankle-brachial index in 29,593 men and women aged 50–64 years. The results were confirmed using 2-sample Mendelian randomization. Lower lung function and emphysema were associated with more atherosclerosis, but these relationships were attenuated after adjustment for cardiovascular risk factors. Lung function was not associated with coronary atherosclerosis in 14,524 never-smokers. No potentially causal effect of lung function on atherosclerosis, or vice versa, was found in the 2-sample Mendelian randomization analysis. Here we show that reduced lung function and atherosclerosis are correlated in the population, but probably not causally related. Assessing lung function in addition to conventional cardiovascular risk factors to gauge risk of subclinical atherosclerosis is probably not meaningful, but low lung function found by chance should alert for atherosclerosis.
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