| 1. |
- Blokland, G. A. M., et al.
(författare)
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Sex-Dependent Shared and Nonshared Genetic Architecture Across Mood and Psychotic Disorders
- 2022
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Ingår i: Biological Psychiatry. - : Elsevier BV. - 0006-3223 .- 1873-2402. ; 91:1, s. 102-117
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sex differences in incidence and/or presentation of schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BIP) are pervasive. Previous evidence for shared genetic risk and sex differences in brain abnormalities across disorders suggest possible shared sex-dependent genetic risk. Methods: We conducted the largest to date genome-wide genotype-by-sex (G×S) interaction of risk for these disorders using 85,735 cases (33,403 SCZ, 19,924 BIP, and 32,408 MDD) and 109,946 controls from the PGC (Psychiatric Genomics Consortium) and iPSYCH. Results: Across disorders, genome-wide significant single nucleotide polymorphism–by-sex interaction was detected for a locus encompassing NKAIN2 (rs117780815, p = 3.2 × 10−8), which interacts with sodium/potassium-transporting ATPase (adenosine triphosphatase) enzymes, implicating neuronal excitability. Three additional loci showed evidence (p < 1 × 10−6) for cross-disorder G×S interaction (rs7302529, p = 1.6 × 10−7; rs73033497, p = 8.8 × 10−7; rs7914279, p = 6.4 × 10−7), implicating various functions. Gene-based analyses identified G×S interaction across disorders (p = 8.97 × 10−7) with transcriptional inhibitor SLTM. Most significant in SCZ was a MOCOS gene locus (rs11665282, p = 1.5 × 10−7), implicating vascular endothelial cells. Secondary analysis of the PGC-SCZ dataset detected an interaction (rs13265509, p = 1.1 × 10−7) in a locus containing IDO2, a kynurenine pathway enzyme with immunoregulatory functions implicated in SCZ, BIP, and MDD. Pathway enrichment analysis detected significant G×S interaction of genes regulating vascular endothelial growth factor receptor signaling in MDD (false discovery rate-corrected p < .05). Conclusions: In the largest genome-wide G×S analysis of mood and psychotic disorders to date, there was substantial genetic overlap between the sexes. However, significant sex-dependent effects were enriched for genes related to neuronal development and immune and vascular functions across and within SCZ, BIP, and MDD at the variant, gene, and pathway levels. © 2021 Society of Biological Psychiatry
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| 2. |
- Stranneheim, Henrik, et al.
(författare)
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Rapid pulsed whole genome sequencing for comprehensive acute diagnostics of inborn errors of metabolism
- 2014
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 15, s. 1090-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Massively parallel DNA sequencing (MPS) has the potential to revolutionize diagnostics, in particular for monogenic disorders. Inborn errors of metabolism (IEM) constitute a large group of monogenic disorders with highly variable clinical presentation, often with acute, nonspecific initial symptoms. In many cases irreversible damage can be reduced by initiation of specific treatment, provided that a correct molecular diagnosis can be rapidly obtained. MPS thus has the potential to significantly improve both diagnostics and outcome for affected patients in this highly specialized area of medicine. Results: We have developed a conceptually novel approach for acute MPS, by analysing pulsed whole genome sequence data in real time, using automated analysis combined with data reduction and parallelization. We applied this novel methodology to an in-house developed customized work flow enabling clinical-grade analysis of all IEM with a known genetic basis, represented by a database containing 474 disease genes which is continuously updated. As proof-of-concept, two patients were retrospectively analysed in whom diagnostics had previously been performed by conventional methods. The correct disease-causing mutations were identified and presented to the clinical team after 15 and 18 hours from start of sequencing, respectively. With this information available, correct treatment would have been possible significantly sooner, likely improving outcome. Conclusions: We have adapted MPS to fit into the dynamic, multidisciplinary work-flow of acute metabolic medicine. As the extent of irreversible damage in patients with IEM often correlates with timing and accuracy of management in early, critical disease stages, our novel methodology is predicted to improve patient outcome. All procedures have been designed such that they can be implemented in any technical setting and to any genetic disease area. The strategy conforms to international guidelines for clinical MPS, as only validated disease genes are investigated and as clinical specialists take responsibility for translation of results. As follow-up in patients without any known IEM, filters can be lifted and the full genome investigated, after genetic counselling and informed consent.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Alzubaidi, H., et al.
(författare)
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Statistical Analysis of Gravel Road Rating
- 2002
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Ingår i: The international journal of pavement engineering. - Nottingham. - 1029-8436 .- 1477-268X. ; 3:1, s. 35-42
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Andersson, Hedvig, et al.
(författare)
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Young adults looking back at their experiences of treatment and care for nonsuicidal self-injury during adolescence: a qualitative study
- 2024
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Ingår i: Child and Adolescent Psychiatry and Mental Health. - : BMC. - 1753-2000. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundNonsuicidal self-injury (NSSI) is associated with stigma, and negative attitudes among healthcare professionals toward NSSI have been reported. A person-centered approach that focuses on how individuals with lived experience of NSSI perceive the treatment and care they receive is invaluable in reducing barriers to help-seeking and improving treatment and mental healthcare services. The aim of the current qualitative study was to explore the perceptions of young adults when they look back upon their experiences of psychiatric treatment for NSSI during adolescence.MethodsTwenty-six individuals with lived experience of NSSI who were in contact with child and adolescent psychiatry during adolescence were interviewed. The interviews were analyzed using thematic analysis.ResultsThree main themes were developed: Changed perceptions in retrospect, The importance of a collaborative conceptualization and Lasting impression of the relationship. Participants' perception of themselves as well as the treatment changed over time. The importance of a joint understanding of NSSI and an agreed-upon treatment focus was emphasized. The relationship to the mental health professionals, and experiences of how NSSI was communicated, were salient several years later.ConclusionsHealthcare professionals need to communicate about NSSI in a respectful manner and include the perspective of the adolescent with lived experience of NSSI in a joint conceptualization of NSSI and treatment focus.
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| 8. |
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| 9. |
- Berglund, Andreas
(författare)
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Prognos av vägars bärförmåga vid tjällossningen : användning av temperatur som nyckeltal
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The global trend towards a warmer climate and temperatures near or just above 0 °C during winter months, will most likely be more common in future. One of the consequences of this climate change could, in a worst-case scenario, be freezing and thawing over a significant part of the winter with corresponding road bearing capacity problems. Bearing capacity problems may lead to increased costs to society when heavy traffic is forced to change route or carry less weight. In addition, road maintenance costs will increase. According to pulp industry calculations, this industry sector will face additional costs in the range of 510-590 Million SEK every year due to road bearing capacity problems. In addition to this, the costs related to the rapidly growing bio fuel industry will be added. If a reliable forecast of load-bearing capacity problems and potential load restrictions on roads can be found, it would be cost effective for road administration and society. This text presents the content of the licentiate work is presented and in what report more information could be found. One aspect of frost damage on roads that is highlighted in the thesis is decision making when conducting a road inventory. In a study conducted within the licentiate work it was shown that the results from different actors performing frost inventory on the same road stretch can vary a lot. There should be efforts made to reduce the individual dependence when performing a road inventory. The main part of the licentiate work deals with a model for the prediction of bearing capacity problems on roads. The work gives an idea of the possibility to use the temperature based model used in Minnesota, USA in Sweden. The evaluation is done by comparing falling weight deflectometer (FWD) test results with the results from the temperature based forecast model. When comparing the FWD results: AREA-parameter and subgrade modulus with results from the Minnesota model, the subgrade modulus seems to have the greatest agreement with the forecast model. However, they both seem to show the overall development of low bearing capacity during thaw. The overall conclusion about the temperature based forecast model is that it seems to give fairly good results and work well. It will work better if it can be further calibrated but it has some flaws if the temperature seesaws around 0 °C. The forecast model should, despite this, be able to assist road holders in Sweden as a planning tool, when dealing with bearing capacity problems during thaw.
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| 10. |
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| 11. |
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| 12. |
- Cabric, Sanja, et al.
(författare)
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Anchoring of vascular endothelial growth factor to surface-immobilized heparin on pancreatic islets : implications for stimulating islet angiogenesis
- 2010
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Ingår i: Tissue engineering. Part A. - : Mary Ann Liebert Inc. - 1937-3341 .- 1937-335X. ; 16:3, s. 961-970
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Tidskriftsartikel (refereegranskat)abstract
- In pancreatic islet transplantation, early revascularization is necessary for long-term graft function. We have shown in in vitro and in vivo models that modification with surface-attached heparin protects the islets from acute attack by the innate immune system of the blood following intraportal islet transplantation. In this study, we have investigated the ability of an immobilized conjugate composed of heparin to bind the angiogenic growth factor vascular endothelial growth factor-A (VEGF-A) as a means of attracting endothelial cells (ECs) to induce angiogenesis and revascularization. We analyzed the capacity of VEGF-A to bind to immobilized heparin and how this affected the proliferation and adherence of ECs to both artificial glass surfaces and islets. Quartz crystal microbalance with dissipation monitoring and slot-blot demonstrated the binding of VEGF-A to heparin-coated surfaces upon which ECs showed protein-dependent proliferation. Also, ECs cultured on heparin-coated glass surfaces exhibited effects upon focal contacts. Heparinized islets combined with VEGF-A demonstrated unaffected insulin release. Further, covering islets with heparin also increased the adhesion of ECs to the islet surface. Immobilized heparin on the islet surface may be a useful anchor molecule for achieving complete coverage of islets with angiogenic growth factors, ultimately improving islet revascularization and engraftment in pancreatic islet transplantation.
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| 13. |
- de Jong, S, et al.
(författare)
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Applying polygenic risk scoring for psychiatric disorders to a large family with bipolar disorder and major depressive disorder
- 2018
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Ingår i: Communications biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 1, s. 163-
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Tidskriftsartikel (refereegranskat)abstract
- Psychiatric disorders are thought to have a complex genetic pathology consisting of interplay of common and rare variation. Traditionally, pedigrees are used to shed light on the latter only, while here we discuss the application of polygenic risk scores to also highlight patterns of common genetic risk. We analyze polygenic risk scores for psychiatric disorders in a large pedigree (n ~ 260) in which 30% of family members suffer from major depressive disorder or bipolar disorder. Studying patterns of assortative mating and anticipation, it appears increased polygenic risk is contributed by affected individuals who married into the family, resulting in an increasing genetic risk over generations. This may explain the observation of anticipation in mood disorders, whereby onset is earlier and the severity increases over the generations of a family. Joint analyses of rare and common variation may be a powerful way to understand the familial genetics of psychiatric disorders.
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| 14. |
- Eckersten, Henrik, et al.
(författare)
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Framtida risker och hot mot svensk spannmåls- respektive mjölkproduktion : en analys av forskningsbehov för att bedöma risker
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Vad är syftet med denna Riskanalys? Svensk spannmåls- och mjölkproduktion beror på många faktorer av vilka flera är så kallade biofysiska, dvs i allt väsentligt är de av naturvetenskaplig karaktär (t ex väder, sjukdomar mm). En del förändringar i dessa förutsättningar utgör hot. Vår studie avser att identifiera några av dessa hot och utvärdera, utifrån vetenskapligt testade metodiker, sannolikheten för att de orsakar en skada på produktionen. Detta kräver dock ett mycket omfattande arbete och i denna studie har vi därför begränsat oss till att (i) strukturera hur en vetenskapligt baserad riskanalys bör gå till, och (ii) göra ett antal preliminära riskanalyser för att (iii) identifiera kunskapsluckor som behöver forskas på för att analysen ska kunna antas vila på en vetenskaplig grund. Vad menar vi med Risk? Vi har definierat risk som sannolikheten att ett hot orsakar en viss negativ konsekvens för den skyddsvärda tillgången. Av dessa termer är kanske den sistnämnda den mest centrala. Vad är det vi vill skydda? Vi har valt ut två tillgångar, Sveriges nationella spannmåls- respektive mjölkproduktion och avser då den produktion som lämnar gården, eller används inom gården, och att de skyddas så att de förblir ungefär av den omfattningen de har i dagsläget. Hoten mot denna produktion har valts utifrån förslag från tidigare studier, workshop, tillgången på experter och att hoten ska vara av biofysisk karaktär. Vilket hot som verkligen utgör en stor risk vet vi ju dock inte förrän efter riskanalysen är utförd och valen av hot bygger därför på en preliminär uppskattning. Biofysisk karaktär innebär att vi främst analyserat naturvetenskapliga hot. Hoten orsakar effekter på produktionen i mätbara termer som sedan översätts till en mer abstrakt skala från ingen till extremt negativ konsekvens. Beroende på olika osäkerhetsfaktorer erhåller vi flera konsekvensvärden för ett givet hot, och fördelningen av dessa på konsekvensskalan utgör ett mått på sannolikheten. Risken anges alltså som ett förhållande mellan konsekvens och sannolikhet. Varför har vi gjort denna systemavgränsning? Riskanalysen har två huvudaktörer; riskhanteraren som definierar vad som ska anlyseras och analysfunktionen som utför analysen. Riskhanteraren är i vårt fall styrgruppen för SLUs forskningsprogram Framtidens lantbruk (FA, 2015) som har definierat typen av hot och de skyddsvärda tillgångarna som ska analyseras. Vi som utfört denna studie är analysfunktionen, och har alltså dessa definitioner som en utgångspunkt. Om vi ändå tillåter oss att spekulera kring valet av spannmåls- respektive mjölkproduktionen så kan det motiveras av SLU's nationella ansvar vad avser den vetenskapliga kompetensen inom de areella näringarna. Ett fokus på biofysiska hot motiveras av att dessa är potentiellt stora och växande, såsom t ex är fallet vad avser klimatförändringar. Riskanalyser av denna typ bildar centrala underlag för att formulera olika strategier, t ex angående livsmedelsförsörjning. Hur har arbetet gått till? Riskanalyserna har utförts för ett antal "krisscenarier"; fyra avseende hot mot spannmålsproduktionen (Radioaktivt-nedfall, Virus-i-spannmål, Herbicidresistens och Extremt-sommarväder) och tre avseende mjölkproduktionen (Leptospiros-utbrott, Foderimport-stopp och Värmebölja). Analysen tar sin utgångspunkt i ett omvärldsscenario som definierar de yttre förutsättningarna för vad som antas inträffa. Detta ligger till grund för att identifiera troliga hot mot produktionen och vilka åtgärder som förväntas vidtas. Vi har sedan utgått från att dessa hot och åtgärder verkligen har hänt när vi mha våra förklaringsmodeller bestämt effekterna på produktionen i termer av mätbara enheter ("metrics"; t ex procentuell minskning av lokal eller regional veteproduktion). Dessa effekter tolkas/integreras sedan till en konsekvens för, helst den nationella, men i realiteten främst den regionala produktionen i fem nivåer (ingen, liten, måttlig, stor respektive extrem). Osäkerheter i bedömningarna innebär att flera alternativa konsekvenser erhålls, för ett givet hot, och som ligger till grund för en sannolikhetsbedömning. Analyserna har gjorts av experter inom respektive hots vetenskapliga område, men som haft begränsade förutsättningar (av tidsskäl) att göra tillräckligt många bedömningar för att erhålla ett tillförlitligt mått på sannolikhetsfördelningen (osäkerheten). Istället har vi, vilket också är ett huvudsyfte med studien, huvudsakligen försökt identifiera de kunskapsluckor i förklaringsmodellerna som begränsat våra möjligheter att kunna göra vetenskapligt baserade bedömningar av effekterna (se vidare Appendix 3). Vad är resultatet? Vi har gjort vissa grova skattningar av sannolikheten trots det bristfälliga antalet bedömningar av konsekvenser. Om ett radioaktivt nedfall sker i en region får det extrema konsekvenser för dess spannmålsproduktion på regional nivå. Ett omfattande angrepp av jordburna virus orsakar en måttlig eller stor konsekvens. En utvecklad herbicidresistens hos ogräsen orsakar i huvudsak en liten till måttlig konsekvens. En extremt torr sommar kan ett år orsaka en stor konsekvens och ett annat år ingen alls. Likaledes orsakar en Regnig-sensommar i ca hälften av fallen ingen konsekvens, men för de resterande åren kan alla grader av konsekvenser uppstå på spannmålsproduktionen. För mjölkproduktionen orsakar samtliga tre hot (Leptospiros-utbrott, Foderimport-stopp och Värmebölja) en liten till måttlig konsekvens. Vad avser ett importsopp för foder är detta under förutsättning att olika åtgärdsprogram kombineras. Om fokus läggs på endast ett åtgärdsprogram ökar risken väsentligt. Dessa skattningar ska alltså inte betraktas som en vetenskapligt baserad analys i nuläget, utan demonstrerar främst exempel på resultat från sådana analyser. Skattningarna har hjälpt oss att identifiera vilka kunskaper vi saknar för att analyserna ska kunna betraktas som vetenskapligt baserade (se vidare Tabell 4.3a; sammanfattningar av respektive scenario finns i Resultatdelen). Analyserna har ibland också lett till att vi identifierat följdhändelser som faller utanför systemavgränsningen för vår studie och som andra studier har till uppgift att utreda. Många av de hot vi analyserat kan leda till betydande ekonomiska konsekvenser för enskilda företag, vilket i sin tur utgör hot mot produktionen. För denna analys krävs dock socioekonomiska analyser. Vi ser här också kopplingar mellan krisscenarier som är av biofysisk karaktär, t ex kan foder kontaminerat med radioaktivt cesium utgöra ett hot mot mjölkproduktionen. Vår studie har dock bara analyserat ett krisscenarios inverkan på antigen spannmåls- eller mjölkproduktionen.Vilka är de viktigaste slutsatserna? En central fråga är: Hur trovärdiga/säkra är dessa förutsägelser? Risk avser en förutsägelse om något som ännu inte hänt. Det första som behövs är alltså någon form av modell. Dessa modeller kan vara av olika sort i termer av vilken empirisk kunskap de använder för extrapolering (t ex funktioner, behandlingseffekter, mm), om de är objektiva och om de är transparenta. Alla modeller är osäkra i någon mening. Dock saknas i alla de fall vi undersökt mått på modellernas förutsägelseförmåga (med något enstaka undantag). En allmän slutsats blir att forskningen behöver inriktas mot att testa modellernas förutsägelseförmåga mot observationer för att kunna bidra till en vetenskapligt baserad riskanalys av spannmåls- respektive mjölkproduktionen. Detta innebär att experiment- och försöksupplägg behöver göras utifrån hypoteser (modeller) om hur de dynamiska förloppen beror på varierande förutsättningar och omgivningsförhållanden. T ex behöver de statistiska relationerna för hur Extremt-sommarväder påverkar spannmålsproduktionen, som används i vår studie, kompletteras med tester av grödmodeller som kan beakta flera vädervariablers samtida variationer i både tid och rum. För kunskapsluckor som är specifika för respektive hot, se Tabell 4.4Sammanfattningsvis behövs (i) fler förutsägelser av respektive potentiellt hots konsekvenser på produktionen, med modeller som har någon form av graderad tillförlitlighet, för att erhålla mått på osäkerheter. Dessutom behövs det (ii) tester av hypoteser för uppskalningar från kontrollerade experiment och försök (på en liten skala i tid och rum) till regional och nationell skala över flera år, och (iii) utveckling av metodiker för hur sannolikheter för hot, åtgärder respektive konsekvenser kan kombineras till en sannolikhetsfördelning som inbegriper bedömningsosäkerheter för alla dessa faktorer. Troligtvis behövs också att fler potentiella biofysiska hot analyseras. Hur går vi vidare? En mer fullständig riskanalys som inkluderar alla potentiellt stora hot mot produktionen, och samtidigt är vetenskapligt baserad, kräver att potentiella hot utreds kontinuerligt inom respektive produktionsrelaterat ämnesområde vid SLU. Detta kräver troligen att verksamheter som testar hypoteser för att förutsäga effekter av hot knyts nära den experimentella forskningen och experter inom respektive ämnesområde. Det krävs troligen också att en syntesverksamhet etableras på en ämnesövergripande nivå där metodiker kan standardardiseras, och olika hot och dess konsekvenser kan jämföras och kombineras. En sådan fungerande verksamhet behöver utvidga systemgränserna jämfört med vår studie, genom att sannolikheter för att hot uppkommer och att åtgärder faktiskt vidtas, också bedöms. Dessa sannolikheter behöver sedan integreras med sannolikheterna för konsekvenserna på produktionen. Därefter kan riskanalysen utökas till att inbegripa en mer a
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| 15. |
- Edvardsson, Karin, et al.
(författare)
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Dust suppressants efficiency study : in situ measurements of dust generation on gravel roads
- 2012
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Ingår i: The international journal of pavement engineering. - : Informa UK Limited. - 1029-8436 .- 1477-268X. ; 13:1, s. 11-31
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Tidskriftsartikel (refereegranskat)abstract
- Dust suppressants were applied on fifteen 1 km long test sections at four sites in Sweden during three summer seasons with the objective to compare their relative efficiency and determine minimum application rates in Nordic climate. Dust generation from the test sections was measured both visually and by PM10 measurements. All products except lignosulphonate, sugar and bitumen emulsion showed acceptable efficiency. Chloride solutions were the most efficient. Results indicate the possibility to reduce application rates of chlorides by applying them as solutions instead of solids. The minimum application rate for a chloride solution was estimated at 0.8m(3)/km, which is equivalent to a rate reduction of 50% by weight compared with traditionally applied rates of solid chloride. The results are expected to reduce life cycle costs for gravel roads and contribute to environmental gains by reducing the release of dust into the atmosphere and chemicals into the environment.
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| 16. |
- Edvardsson, Karin, et al.
(författare)
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Impact of fine materials content on the transport of dust suppressants in gravel road wearing courses
- 2011
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Ingår i: Journal of materials in civil engineering. - 0899-1561 .- 1943-5533. ; 23:8, s. 1163-1170
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Tidskriftsartikel (refereegranskat)abstract
- A significant problem when dust-suppressing agents are used on gravel roads is that they tend to leach during rainfall. The purpose of this study is to illustrate this problem by using laboratory studies and studies in situ. Both capillary rise and leaching of suppressants were examined by using cylinders filled with wearing course material. Chloride was more prone than lignosulphonate to transport upwards by means of capillary rise, and therefore, it showed a more effective performance over a longer period of time. Optimal percentages of fine material for minimal lignosulphonate and chloride leaching were found to be 15% by weight and 10-15% by weight, respectively. Ions of calcium chloride seemed to flocculate clay particles, which probably prevents them from leaching. To study the in situ longevity of fine material in general, calcium carbonate, mesa, was used as a marker. The fine material in gravel wearing courses must be replenished regularly. Mesa loss was up to 80% after 1 year.
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| 17. |
- Edvardsson, Karin, et al.
(författare)
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Methods for Quantification of Lignosulphonate and Chloride in Gravel Wearing Courses
- 2010
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Ingår i: International Journal on Road Materials and Pavement Design. - 1468-0629 .- 2164-7402. ; 11:1, s. 171-185
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Tidskriftsartikel (refereegranskat)abstract
- Due to oxidation, breakdown, and leaching, dust suppressants will be lost from the gravel road surface. Methods for residual dust suppressant concentration supervision are a valuable tool for estimating life-length and optimal application rates, and, hence, efficiency of different products. The objective of this study was to identify methods for quantitative analyses of lignosulphonate and chloride, develop and adapt the methods for application on a gravel matrix, and validate the methods using samples collected in-situ. Results strongly suggest that the reliability and repeatability of the developed methods (23% for lignosulphonate and 30% for chloride, respectively) are acceptable for determination of relative variations in residual concentrations of dust suppressed gravel wearing courses.
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| 18. |
- Edvardsson, Karin, et al.
(författare)
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Monitoring of dust emission on gravel roads : Development of a mobile methodology and examination of horizontal diffusion
- 2009
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 43:4, s. 889-896
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Tidskriftsartikel (refereegranskat)abstract
- Traffic-generated fugitive dust on gravel roads impairs visibility and deposits on the adjacent environment. Particulate matter smaller than 10 mu m in diameter (PM10) is also associated with human health problems. Dust emission strength depends on the composition of granular material, road moisture, relative humidity, local Climate (precipitation, wind velocity, etc.), and vehicle characteristics. The objectives of this study Were to develop a reliable and rapid mobile methodology to measure dust concentrations on gravel roads, evaluate the precision and repeatability of the methodology and correspondence with the currently used Visual assessment technique. Downwind horizontal diffusion was studied to evaluate the risk of exceeding the maximum allowed particulate matter concentration in ambient air near gravel roads according to European Council Directive [European Council Directive 1999/30/EC of 22 April 1999 relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air. Official Journal of the European Communities. L163/41.]. A TSI DustTrak Aerosol Monitor was mounted on an estate car travelling along test sections treated with various dust suppressants. Measured PM10 concentrations were compared to Visual assessments performed at the same time. Airborne particles were collected in filters Mounted behind the vehicle to compare the whole dust fraction with the PM10 concentration. For measuring the horizontal diffusion, DustTraks were placed at Various distances downwind of a dusty road section. The mobile methodology was vehicle and speed dependent but not driver dependent with pre-specified driving behaviours. A high linear correlation between PM10 of different vehicles makes relative measurements of dust concentrations possible. The methodology gives continuous data series, mobility, and easy handling and provides fast, reliable and inexpensive measurements for estimating road conditions to make road maintenance more efficient. Good correlations between measured PM10-values, visually assessed dust generation and dust collected in filters were obtained. PM10 seems to be correlated to the whole dust fraction that impairs visibility on gravel roads. A decay in PM10 concentration as a function of distance from the road was observed. Measured particles principally did not travel further than 45 m from the road. The risk of exceeding the PM10 concentration stated in the EC-directive seems small.
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| 19. |
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| 20. |
- Engström, Björn, et al.
(författare)
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Anchorage and bond in high strenght concrete
- 2000
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Ingår i: Bond of reinforcement in concrete. - Lausanne : International Federation for Structural Concrete / Task Group Bond Models. - 2883940509 ; , s. 99-156
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 21. |
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| 22. |
- Fransson, Per-Anders, et al.
(författare)
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Analysis of Postural Control Adaptation during Galvanic and Vibratory Stimulation
- 2001
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Ingår i: Proc. 23rd Annual EMBS International Conference (EMBC2001). ; , s. 1170-1173
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Konferensbidrag (refereegranskat)abstract
- The objective for this study was to investigate whether the postural control adaptation during galvanic stimulation of the vestibular nerve were similar to that found during vibration stimulation to the calf muscles. A method for adaptation analysis was used to analyze the evoked changes of posture, stimulus responses and the motion dynamics. The adaptive adjustments of postural control were similar during galvanic and vibratory stimulation, which suggests that the adaptation operate in the same way independent of the receptor systems affected by the disturbance. There was however a difference in the dynamic feedback properties of the measured responses.
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| 23. |
- Fransson, Per-Anders, et al.
(författare)
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Analysis of Short- and Long-Term Effects of Adaptation in Human Postural Control
- 2002
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Ingår i: Biological Cybernetics. - : Springer Science and Business Media LLC. - 1432-0770 .- 0340-1200. ; 86:5, s. 355-365
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Tidskriftsartikel (refereegranskat)abstract
- The short-term (i.e., days) and long-term (i.e., months) effects of adaptation to posturography examinations were investigated in 12 normal subjects who were repeatedly examined for five consecutive days and again after 90 days. The examinations were conducted both with eyes open and closed, and the perturbations were evoked by a pseudorandomly applied vibration stimulation to the calf muscles. The evoked anteroposterior responses were analyzed with a method considering adaptation in the slow changes in posture and in the stimulus-response relationship. Repetition of examinations on a daily basis revealed a gradual improvement of postural-control performance. The body sway induced by the stimulation was significantly reduced and the dynamical properties changed. Most of the improvements remained after 90 days, but some parameters such as the complexity of the control system used were increased to the initial level. The results confirm previous observations that postural control contains several partially independent adaptive processes, observed in terms of alteration of posture and as a progressive reduction of body sway induced by stimulation. The method used for the adaptation analysis in this study could be applied to analyze biological systems with multiple individual adaptive processes with different time courses or characteristics, or where the adaptation processes are related to multiple internal or external factors.
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| 24. |
- Fransson, Per-Anders, et al.
(författare)
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Balance Control and Adaptation during Vibratory Perturbations in Middle-Aged and Elderly Humans.
- 2004
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 91:5-6, s. 595-603
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Tidskriftsartikel (refereegranskat)abstract
- The objective was to investigate if healthy elderly people respond and adapt differently to postural disturbances compared to middle-aged people. Thirty middle-aged (mean age 37.8 years, range 24–56 years) and forty healthy elderly subjects (mean age 74.6 years, range 66–88 years) were tested with posturography. Body sway was evoked by applying pseudorandom vibratory stimulation to the belly of the gastrocnemius muscles of both legs simultaneously. The tests were performed both with eyes open and eyes closed. The anteroposterior body sway was measured with a force platform and analyzed with a method that considers the adaptive changes of posture and stimulation responses. The results showed that middle-aged people generally used a different postural control strategy as compared to the elderly. The elderly responded more rapidly to vibratory perturbation, used more high-frequency (>0.1 Hz) motions and the motion dynamics had a higher degree of complexity. Moreover, the elderly had diminished ability to use visual information to improve balance control. Altogether, despite having an effective postural control adaptation similar to that of middle-aged people, the elderly had more difficultly in withstanding balance perturbations. These findings suggest that the balance control deterioration associated with aging cannot be fully compensated for by postural control adaptation.
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| 25. |
- Fransson, Per-Anders, et al.
(författare)
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Deep Brain Stimulation in the Subthalamic Nuclei Alters Postural Alignment and Adaptation in Parkinson’s Disease
- 2021
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:12
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson’s disease (PD) can produce postural abnormalities of the standing body position such as kyphosis. We investigated the effects of PD, deep brain stimulation (DBS) in the subthalamic nucleus (STN), vision and adaptation on body position in a well-defined group of patients with PD in quiet standing and during balance perturbations. Ten patients with PD and 25 young and 17 old control participants were recruited. Body position was measured with 3D motion tracking of the ankle, knee, hip, shoulder and head. By taking the ankle as reference, we mapped the position of the joints during quiet standing and balance perturbations through repeated calf muscle vibration. We did this to explore the effect of PD, DBS in the STN, and vision on the motor learning process of adaptation in response to the repeated stimulus. We found that patients with PD adopt a different body position with DBS ON vs. DBS OFF, to young and old controls, and with eyes open vs. eyes closed. There was an altered body position in PD with greater flexion of the head, shoulder and knee (p≤0.042) and a posterior position of the hip with DBS OFF (p≤0.014). With DBS ON, body position was brought more in line with the position taken by control participants but there was still evidence of greater flexion at the head, shoulder and knee. The amplitude of movement during the vibration period decreased in controls at all measured sites with eyes open and closed (except at the head in old controls with eyes open) showing adaptation which contrasted the weaker adaptive responses in patients with PD. Our findings suggest that alterations of posture and greater forward leaning with repeated calf vibration, are independent from reduced movement amplitude changes. DBS in the STN can significantly improve body position in PD although the effects are not completely reversed. Patients with PD maintain adaptive capabilities by leaning further forward and reducing movement amplitude despite their kyphotic posture.
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| 26. |
- Fransson, Per-Anders, et al.
(författare)
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Deep brain stimulation in the subthalamic nuclei alters postural alignment and adaptation in Parkinson's disease
- 2021
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:12
-
Tidskriftsartikel (refereegranskat)abstract
- Parkinson's disease (PD) can produce postural abnormalities of the standing body position such as kyphosis. We investigated the effects of PD, deep brain stimulation (DBS) in the subthalamic nucleus (STN), vision and adaptation on body position in a well-defined group of patients with PD in quiet standing and during balance perturbations. Ten patients with PD and 25 young and 17 old control participants were recruited. Body position was measured with 3D motion tracking of the ankle, knee, hip, shoulder and head. By taking the ankle as reference, we mapped the position of the joints during quiet standing and balance perturbations through repeated calf muscle vibration. We did this to explore the effect of PD, DBS in the STN, and vision on the motor learning process of adaptation in response to the repeated stimulus. We found that patients with PD adopt a different body position with DBS ON vs. DBS OFF, to young and old controls, and with eyes open vs. eyes closed. There was an altered body position in PD with greater flexion of the head, shoulder and knee (p≤0.042) and a posterior position of the hip with DBS OFF (p≤0.014). With DBS ON, body position was brought more in line with the position taken by control participants but there was still evidence of greater flexion at the head, shoulder and knee. The amplitude of movement during the vibration period decreased in controls at all measured sites with eyes open and closed (except at the head in old controls with eyes open) showing adaptation which contrasted the weaker adaptive responses in patients with PD. Our findings suggest that alterations of posture and greater forward leaning with repeated calf vibration, are independent from reduced movement amplitude changes. DBS in the STN can significantly improve body position in PD although the effects are not completely reversed. Patients with PD maintain adaptive capabilities by leaning further forward and reducing movement amplitude despite their kyphotic posture.
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| 27. |
- Fransson, Per-Anders, et al.
(författare)
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Exploring the Effects of Deep Brain Stimulation and Vision on Tremor in Parkinson's Disease : Benefits from Objective Methods
- 2020
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Ingår i: Journal of NeuroEngineering and Rehabilitation. - : Springer Science and Business Media LLC. - 1743-0003. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Tremor is a cardinal symptom of Parkinson's disease (PD) that may cause severe disability. As such, objective methods to determine the exact characteristics of the tremor may improve the evaluation of therapy. This methodology study aims to validate the utility of two objective technical methods of recording Parkinsonian tremor and evaluate their ability to determine the effects of Deep Brain Stimulation (DBS) of the subthalamic nucleus and of vision.METHODS: We studied 10 patients with idiopathic PD, who were responsive to L-Dopa and had more than 1 year use of bilateral subthalamic nucleus stimulation. The patients did not have to display visible tremor to be included in the study. Tremor was recorded with two objective methods, a force platform and a 3 dimensional (3D) motion capture system that tracked movements in four key proximal sections of the body (knee, hip, shoulder and head). They were assessed after an overnight withdrawal of anti-PD medications with DBS ON and OFF and with eyes open and closed during unperturbed and perturbed stance with randomized calf vibration, using a randomized test order design.RESULTS: Tremor was detected with the Unified Parkinson's Disease Rating Scale (UPDRS) in 6 of 10 patients but only distally (hands and feet) with DBS OFF. With the force platform and the 3D motion capture system, tremor was detected in 6 of 10 and 7 of 10 patients respectively, mostly in DBS OFF but also with DBS ON in some patients. The 3D motion capture system revealed that more than one body section was usually affected by tremor and that the tremor amplitude was non-uniform, but the frequency almost identical, across sites. DBS reduced tremor amplitude non-uniformly across the body. Visual input mostly reduced tremor amplitude with DBS ON.CONCLUSIONS: Technical recording methods offer objective and sensitive detection of tremor that provide detailed characteristics such as peak amplitude, frequency and distribution pattern, and thus, provide information that can guide the optimization of treatments. Both methods detected the effects of DBS and visual input but the 3D motion system was more versatile in that it could detail the presence and properties of tremor at individual body sections.
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| 28. |
- Fransson, Per-Anders, et al.
(författare)
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Methods for Evaluation of Postural Control Adaptation
- 2000
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Ingår i: Gait & Posture. - 1879-2219. ; 12:1, s. 14-24
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Tidskriftsartikel (refereegranskat)abstract
- New methods were developed to determine the dynamic changes of postural control during the initial exposure to large perturbances of stance. The adjustments of postural control over time in measured anteroposterior torque, were investigated in ten normal subjects. Perturbations of stance were evoked by two high intensity vibrators applying pseudorandom stimulation either to the calf muscles or the paravertebral muscles of the neck. The new methods use a system identification approach, which distinguishes between feedback control, adaptation of postural responses and adaptation to stimulus. This approach makes it possible to quantify motion dynamics and complexity, stimulus impact and adjustments of postural control. Quantification of the different adaptive responses could be useful for diagnostic purposes, in evaluating treatment efficacy and patient progress in rehabilitation programs.
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| 29. |
- Fransson, Per-Anders, et al.
(författare)
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Postural Control Adaptation during Galvanic Vestibular and Vibratory Proprioceptive Stimulation
- 2003
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Ingår i: IEEE Transactions on Biomedical Engineering. - 1558-2531. ; 50:12, s. 1310-1319
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Tidskriftsartikel (refereegranskat)abstract
- he objective for this study was to investigate whether the adaptation of postural control was similar during galvanic vestibular stimulation and during vibratory proprioceptivestimulation of the calf muscles. Healthy subjects were tested during erect stance with eyes open or closed. An analysis method designed to consider the adaptive adjustments was used to evaluate the motion dynamics and the evoked changes of posture and stimulation response.Galvanic vestibular stimulation induced primarily lateral body movements and vibratory proprioceptive stimulation induced anteroposterior movements. The lateral body sway generated by the galvanic stimulation was proportionally smaller and contained more high-frequency movements (0.1 Hz) than the anteroposterior body sway induced by the vibratory stimulation. The adaptive adjustments of the body sway to the stimulation had similar time course and magnitude during galvanic and vibratory stimulation. The perturbations induced by stimulation were gradually reduced within the same time range (15–20 s) and both kinds of stimulation induced a body leaning whose direction was dependent on stimulus. The similarities in the adjustmentpatterns suggest that postural control operates in the same way independent of the receptor systems affected by the disturbance and irrespective of whether the motion responses were induced in a lateral or anteroposterior direction.
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| 30. |
- Friberg, Örjan, et al.
(författare)
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Cost effectiveness of local collagen-gentamicin as prophylaxis for sternal wound infections in different risk groups
- 2006
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 40:2, s. 117-125
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: In a randomized trial addition of local collagen-gentamicin in the sternal wound reduced the rate of sternal wound infection (SWI) to about 50% compared to intravenous prophylaxis alone. The aim of the present study was to evaluate the economic rationale for its use in every-day clinical practice. This includes the question whether high-risk groups that may have particular benefit should be identified. DESIGN: For each patient with SWI in the trial the costs attributable to the SWI were calculated. Risk factors for SWI were identified and any heterogeneity of the effect of the prophylaxis examined. RESULTS: The mean cost of a SWI was about 14500 Euros. A cost effectiveness analysis showed that the prophylaxis was cost saving. The positive net balance was even higher in risk groups. Assignment to the control group, overweight, diabetes, younger age, mammarian artery use, left ventricular ejection fraction <35% and longer operation time were independent risk factors for infection. CONCLUSION: The addition of local collagen-gentamicin to intravenous antibiotic prophylaxis was dominant, i.e. resulted in both lower costs and fewer wound infections.
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| 31. |
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| 32. |
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| 33. |
- Gomez, Stephen, et al.
(författare)
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Effects of Proprioceptive Vibratory Stimulation on Body Movement at 24 and 36 h of Sleep Deprivation
- 2008
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Ingår i: Clinical Neurophysiology. - : Elsevier BV. - 1872-8952 .- 1388-2457. ; 119:3, s. 617-625
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate whether postural stability and adaptation differed after a normal night of sleep, after 24 h (24 SDep) and 36 h (36 SDep) of sleep deprivation while subjected to repeated balance perturbations. Also, to determine whether there was any correlation between subjective alertness scores and objective posturographic measurements. Lastly, to investigate the effects of vision on the stability during sleep deprivation. Methods: Body movements at five locations were recorded in 18 subjects (mean age 23.8 years) using a 3D movement measurement system while subjected with eyes open and closed to vibratory proprioceptive calf stimulation after a normal night of sleep, 24 and 36 SDep. Results: The clearest sleep deprivation effect was reduced ability to adapt head, shoulder and hip movements, both with eyes open and eyes closed. Additionally, several near falls occurred after being subjected to balance perturbations for 2–3 min while sleep deprived. Unexpectedly, postural performance did not continue to deteriorate between 24 and 36 h of sleep deprivation, but showed some signs of improvement. Subjective scores of sleepiness correlated poorly with actual changes in postural control performance. Conclusions: Sleep deprivation might affect postural stability through reduced adaptation ability and lapses in attention. Subjective alertness might not be an accurate indicator of the physiological effects of sleep deprivation. Significance: Sleep deprivation could increase the risk of accidents in attention demanding tasks. There is a need for objective evaluation methods to determine actual performance capacity during sleep deprivation.
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| 34. |
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| 35. |
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| 36. |
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| 37. |
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| 38. |
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| 39. |
- Johansson, Rolf, et al.
(författare)
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Discrimination between Patients with Acoustic Neuroma and with Peripheral Vestibular Lesion by Human Posture Dynamics
- 1994
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 114:3, s. 479-483
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Tidskriftsartikel (refereegranskat)abstract
- A group of normal subjects (n = 17) was compared with two groups of patients, either with vestibular neuritis (n = 18) or with acoustic neuroma (n = 35) by means of posturography when stance was perturbed with vibrators attached to the calf muscles. Dynamic control of human posture was quantified by means of system identification, and the characteristic parameters of swiftness, stiffness, and damping of a transfer function from vibration to force platform response were used for further comparison. Fisher linear discriminant analysis was used to distinguish sets of parameters characteristic of each disease. Hence it was possible to distinguish the vestibular neuritis group both from the normal group (p < 0.01), and from the patients with acoustic neuroma (p < 0.001). The normal group was characterized by a different postural performance, with higher swiftness and stability parameters (stiffness, damping) than those of the patient groups. These findings indicate that there are differences in the dynamic control of posture between the two patient categories, which may require the development of differentiated rehabilitation programs.
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| 40. |
- Johansson, Rolf, et al.
(författare)
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Discrimination of Patients with Acoustic Neuroma and Peripheral Vestibular Lesions with Human Posture Dynamics
- 1995
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 115:S520, s. 27-28
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Tidskriftsartikel (refereegranskat)abstract
- A group of normal subjects (n = 17) was compared with groups of patients with a diagnosis of vestibular neuritis (n = 18), and acoustic neuromas (n = 35). Fisher linear discriminant analysis was applied to distinguish clusters of parameters characteristic for each disease. Hence it was possible to distinguish the vestibular neuritis patients from the normal group with statistical significance (p < 0.01). Also the patients with an acoustic neuroma could be distinguished from the normal subjects with statistical significance (p < 0.05).
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| 41. |
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| 42. |
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| 43. |
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| 44. |
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| 45. |
- Johansson, Rolf, et al.
(författare)
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Human Postural Dynamics
- 1991
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Ingår i: CRC Critical Reviews in Biomedical Engineering. ; 18:6, s. 413-437
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Tidskriftsartikel (refereegranskat)abstract
- The study of posture dynamics is important not only to understand disorders of impaired equilibrium and protective reactions to unexpected displacements of the human body, but also to the design of prosthesis and functional neuromuscular stimulation as aids to patients with impaired postural stability and locomotion. Coordinated control of the body segments is a complex aspect of motor behavior, owing to the multiple degrees of freedom of the controlled system. Several interacting subsystems are involved in the dynamics of human posture and locomotion, including the skeletal, neuromuscular, and sensory systems. Human posture control is maintained by somatosensory, vestibular, and visual feedback, integrated within the locomotor and central nervous systems. Studies of posture dynamics and stability therefore entail the study of mechanical aspects of the human body, its sensory systems, and the principles governing coordination in motion control. In this paper is reviewed some of the research done in the field of human posture dynamics, including such topics as biomechanics, equilibrium, stability, motion coordination, neural feedback, neural control systems modeling, motion strategies, optimality of motion, and adaptation. We consider experimental approaches and theoretical models, as well as the gap between them. Principles for the experimental investigation of control systems are considered.
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| 46. |
- Johansson, Rolf, et al.
(författare)
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Identification of Adaptation in Human Postural Control using GARCH Models
- 2001
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Ingår i: Proceedings of the 40th IEEE Conference on Decision and Control, 2001.. - 0780370619 ; 1, s. 7-12
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Human postural dynamics was investigated in twelve normal subjects by means of a force platform recording body sway induced by bipolar transmastoid galvanic stimulation of the vestibular nerve and labyrinth. We modeled the stabilizing forces actuated by the feet as resulting from complex muscular activity subject to feedback of body velocity and position. Time series analysis demonstrated that a transfer function from stimulus to sway-force response with specific parameters could be identified. In addition, adaptation to the vestibular stimulus was demonstrated to exist. Residual GARCH modeling (generalized autoregressive conditional heteroskedasticity) suggested a postural adaptation time constant in the range of 40-50 s. The results suggest means to evaluate adaptive behavior in postural control and in other physiological contexts
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| 47. |
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| 48. |
- Johansson, Rolf, et al.
(författare)
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Identification of Human Postural Dynamics
- 1989
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Ingår i: Proc. IEEE Int. Conference on Control and Applications (ICCON '89), volume RP-3-6, Jerusalem, Israel, 1989.. ; RP-3-6, s. 1-6
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Konferensbidrag (refereegranskat)abstract
- R. Johansson and M. Magnusson. Identification of human postural dynamics. Proc. IEEE Int. Conference on Control and Applications (ICCON '89), volume RP-3-6, pages 1--6, Jerusalem, Israel, 1989.
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| 49. |
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| 50. |
- Johansson, Rolf, et al.
(författare)
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Multi-Stimulus Multi-Response Posturography
- 2001
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Ingår i: Mathematical Biosciences. - 0025-5564. ; 174:1, s. 41-59
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Tidskriftsartikel (refereegranskat)abstract
- In this study a method for the analysis of simultaneous multiple measurements of kinematics and stabilizing forces related to human postural dynamics is proposed. Each subject in a group of normal subjects (n=10) was tested with eyes-open and eyes-closed with simultaneous but uncorrelated vestibular and proprioceptive stimuli in order to investigate the contributions of individual sensory feedback loops. Statistical analysis was made by means of multi-input multi-output identification of a transfer function from stimuli to stabilizing forces of the feet and the resulting body position, the transfer function being compatible with a biomechanical model formulated as a stabilized segmented inverted pendulum subject to feedback of body sway and position. Each individual model estimated is effective in predicting a subject's response to new stimuli and in describing the interacting effects of stimuli on body kinetics. The proposed methodology responds to the current needs of data analysis of multi-stimulus multi-response experiments.
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