| 1. |
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| 2. |
- Andersson, Anna-Carin, et al.
(författare)
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Genetisk variation hos vildaväxter och djur i Sverige : En kunskapsöversikt om svenska arter och populationer, teori och undersökningsmetoder Genetic variation in natural populations of animals and plants in Sweden – a review of case studies, theory and some methods
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sverige har genom Konventionen om biologisk mångfald förbundit sig att bevarasin biologiska mångfald (biodiversitet) på ekosystem-, art- och gennivån. Ettvanligt synsätt är att bevarandet av ekosystem och naturtyper också bevarararter och att bevarandet av arter också bevarar genetisk variation inom arterna.Det finns en ökande insikt om att bevarandet av arter inte nödvändigtvis bevarar den genetiska mångfalden inom arterna. Bevarandet av genetisk variationhar hittills fått relativt liten uppmärksamhet inom den praktiska naturvården.På senare år har en del forskare argumenterat för att bevarandearbetetkanske borde fokuseras på att försöka förhindra utdöenden av genetisktdistinkta populationer snarare än att förhindra att arter dör ut. Förespråkarnamenar att man genom att satsa på att bevara genetiskt distinkta populationerbättre bevarar en arts evolutionära potential och anpassningsförmåga. På såsätt minskar risken att arten dör ut även i ett längre tidsperspektiv.Naturvårdsverket fick ett regeringsuppdrag 2006 att ”i samråd med Statensjordbruksverk, Skogsstyrelsen, Fiskeriverket och Sveriges lantbruksuniversitet,ta fram ett nationellt handlingsprogram för bevarande av genetisk variation hosvilda växter och djur.” Den här kunskapsöversikten är en del av underlagetinom uppdraget och har två huvudmålsättningar.Den första målsättningen med kunskapsöversikten är att beskriva den genetiska variationen i svenska populationer utifrån ett antal teman. Dessa teman ärvalda för att belysa vilka generella frågeställningar och problem som i dagslägetidentifieras som betydelsefulla inom den bevarandegenetiska forskningen. Varjetemaavsnitt redovisar det internationella forskningsläget, med exempel på relevanta genetiska studier av svenska organismer.Kunskapsöversiktens andra målsättning är att göra ämnesområdet genetikmer lättillgängligt för personer som inte har arbetat med genetiska frågeställningar tidigare eller de som vill repetera den teoretiska bakgrunden. Den somhar kunskap i populationsgenetiska och evolutionära processer behöver inteläsa detta för att kunna tillgodogöra sig resten av kunskapsöversikten. Kunskapsöversiktens syfte är inte att ge en heltäckande redogörelse för allagenetiska studier som är gjorda i Sverige. Studier före 1997 finns sammanställdai två tidigare rapporter (Laikre & Ryman 1997; Lönn m.fl. 1998). Dessa rapporter är fortfarande mycket aktuella. Eftersom det sker mycket genetiskforskning i Sverige och andra länder, gör den här kunskapsöversikten inteanspråk på att samla all nyvunnen genetisk kunskap om vilda växter och djursedan 1997, utan fokus ligger på de processer som kan antas förändra dengenetiska variationen i vilda populationer utifrån ett svenskt perspektiv.Nyttan av genetisk mångfald. Genetiska skillnader mellan individer, dengenetiska variationen, utgör grunden för all evolution och anpassning. Om allaindivider av en art är genetiskt identiska sätts evolutionen ur spel, med följd attarten inte kan anpassa sig till nya situationer t.ex. de klimatförändringar somförväntas ske till följd av mänskliga utsläpp av växthusgaser. Att mäta dengenetiska variationen och sätta den i samband med evolutionär förändring och ekologisk funktion i vilda populationer är forskningsmässigt mycket krävande.Dock visar en sammanfattande studie av ett stort antal växtstudier ett tydligtsamband mellan populationsstorlek, genetisk variation och olika mått på fertilitetoch livsduglighet, och en annan att ålgräsängar bestående av flera genotypervar mindre känsliga för miljöförändringar, växte tätare och hyste fler smådjur,än genetiskt enhetliga ålgräsängar.Mänskliga aktiviteter kan ha negativa konsekvenser för den genetiskamångfalden och därmed för anpassningsförmågan. Oavsett om variationen ärtill nytta för dagens populationer vet vi inte säkert vilka egenskaper som blirnödvändiga för överlevnaden i en ny miljösituation.Genetisk utarmning av små populationer. Minskad populationsstorlek ärett problem för många djur och växter i människopåverkade områden. Små,isolerade populationer förlorar genetisk variation p.g.a. slumpmässiga, lokalaprocesser (genetisk drift), och på sikt kan även anpassningsförmågan påverkas.Undersökningar visar att många populationer är tillräckligt små och isoleradeför att påverkas av genetisk utarmning, och att utarmade populationer ofta harlägre fertilitet och överlevnadsförmåga som en följd av ökad inavel eller att värdefulla alleler gått förlorade. Enligt flera studier kan det dock räcka med ettfåtal immigranter för att motverka negativa effekter av inavel. Däremot är detsvårt att dra generella slutsatser om hur genetisk utarmning påverkar populationers långsiktiga anpassningsförmåga utifrån de få studier som hittills utförts.Genetisk mångfald efter genflöde och hybridisering. Mänskliga aktiviteterhar i många fall medfört ett ökat genutbyte mellan naturliga djur- och växtpopulationer. Ett stort eller långväga genflöde kan påverka de populationersom tar emot genflödet. Det finns flera fall där mänskliga aktiviteter ökat genflödet genom att skapa gränszoner eller ”hybridmiljöer” där genetiskt olikapopulationer eller närbesläktade arter kunnat mötas och utbyta gener medvarandra. Hos flera arter, t.ex. skogshare respektive växten gulluzern vet manatt gener från införda eller domesticerade släktingar (fälthare resp. blåluzern)spridits ut i den svenska naturen. Däremot saknar vi fortfarande kunskap omdet genflöde som sker när nyanlagda vägslänter besås med utländskt gräsfröeller när utplanterade skogsträd, fåglar och fiskar med främmande bakgrundkommer i kontakt med inhemska bestånd i Sverige. Studier av bl.a. lax visar att genflöde kan vara skadligt genom att ge upphovtill hybrider med låg fertilitet eller livskraft (utavelsdepression). I andra fall hargenflödet gått så långt att arters särprägel hotas, som i fallet med de individfattiga öländska bestånden av silverviol som lätt bildar hybrider med andraarter. Ibland har det uppstått populationer med förmåga att invadera naturligaekosystem efter det att människan underlättat hybridisering mellan närbesläktade arter. Negativa effekter av genflöde måste också beaktas när naturvårdsprojekt avser förstärka populationer genom att tillföra uppfödda individer ellerindivider från andra, avlägsna populationer.Genetiska effekter av beskattning. Många djur- och växtarter utsätts för enregelbunden beskattning i form av fiske, jakt eller skogsbruk. Beskattning förväntas bl.a. öka risken för genetisk utarmning genom att minska den genetiskteffektiva populationsstorleken. I en studie av torsk ledde lokal beskattning tillett ökat inflöde av individer (och gener) från andra populationer, med följd att även det storskaliga variationsmönstret också påverkades. Det finns flera exempel på beskattade djurpopulationer som genomgått en riktad evolutionär förändring, som ett resultat av att beskattningen varit selektiv. I flera fall har dennaförändring minskat populationens förmåga att återhämta sig. Genetisk mångfald och pågående habitat- och klimatförändringar. Lokalanpassning innebär att populationer av en art är genetiskt anpassade till olikamiljötyper. Förmågan att anpassa sig utgör populationers evolutionära potentialoch denna är generellt sett större ju mer genetisk variation som finns i en population. Det finns många exempel på svenska arter som utvecklat lokalt anpassadepopulationer i vissa miljöer, t.ex. strandsnäcka, blåmussla, sill, storspigg, spåtistel, tall, och vitklöver. Förekomsten av lokala anpassningar betyder attindivider från olika populationer inte är direkt utbytbara – lokalt anpassadepopulationer har ett bevarandevärde i sig. Lokal anpassning är därigenom enviktig aspekt vid restaurering, stödutsättning och utnyttjande av populationer.För varje typ av anpassning behövs specifik genetisk variation och hur dennavariation är fördelad inom och mellan populationer samt i hur hög grad variationen kan spridas genom genflöde är i huvudsak okänt och ett område där viktig kunskap saknas. Genetisk särprägel hos svenska populationer. Sverige har få endemiska arteroch de som finns har uppkommit i sen tid som resultat av lokala processer(hybridisering, polyploidisering). Samtidigt finns det många genetiskt särprägladepopulationer. Populationerna är olika för att de har olika ursprung och invandringsvägar eller för att de är anpassade till sin lokala miljö. Taxonomiska enheter som arter, varieteter och former, liksom indelningar i evolutionärt signifikanta enheter och skötselenheter avspeglar en genetisk differentieringsom skett inom eller utanför landet. Genetiskt skilda grupper kan vara svåra atturskilja morfologiskt (de är kryptiska) och det finns flera studier där man medhjälp av molekylära markörer kunnat upptäcka tidigare okända genetiskstruktur hos svenska arter.Lönn m.fl. (1998) framhöll att populationer med en huvudsaklig utbredning i Sverige inte är marginella ur ett genetiskt perspektiv, medan arter som harhuvudsaklig sydlig utbredning och randpopulationer i Sverige är mindre genetiskt variabla här. I många fall är svenska populationer minst lika variabla sompopulationer i områden som inte varit nedisade under den senaste istiden. Dessamönster har bekräftats av senare undersökningar. Likaså styrker senare studieratt populationer från Öland och Gotland, Östersjön med dess stränder,fjällvärlden och det gamla odlingslandskapet är genetiskt särpräglade. Varjeförlorad population innebär en risk att värdefull genetisk variation – och därmed anpassningsförmåga – också går förlorad. Eftersom den genetiska mångfalden återfinns i enskilda popul
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| 3. |
- Andersson, Carin, et al.
(författare)
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Bandsawing. Part I: cutting force model including effects of positional errors, tool dynamics and wear
- 2000
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 227-236
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a mechanical cutting force model for bandsawing. The model describes the variation in cutting force between individual teeth and relates it to initial positional errors, tool dynamics and edge wear. Bandsawing is a multi-tooth cutting process, and the terminology of the cutting action is discussed and compared with other cutting processes. It will also be shown that the setting pattern and the preset feed govern the cutting data.
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| 4. |
- Andersson, Carin, et al.
(författare)
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Experimental studies of cutting force variation in face milling
- 2011
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Ingår i: International Journal of Machine Tools & Manufacture. - : Elsevier BV. - 0890-6955. ; 51:1, s. 67-76
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper is to present a developed cutting force model for multi-toothed cutting processes, including a complete set of parameters influencing the cutting force variation that has been shown to occur in face milling, and to analyse to what extent these parameters influence the total cutting force variation for a selected tool geometry. The scope is to model and analyse the cutting forces for each individual tooth on the tool, to be able to draw conclusions about how the cutting action for an individual tooth is affected by its neighbours. A previously developed cutting force model for multi-toothed cutting processes is supplemented with three new parameters; eccentricity of the spindle, continuous cutting edge deterioration and load inflicted tool deflection influencing the cutting force variation. A previously developed milling force sensor is used to experimentally analyse the cutting force variation, and to give input to the cutting force simulation performed with the developed cutting force model. The experimental results from the case studied in this paper show that there are mainly three factors influencing the cutting force variation for a tool with new inserts. Radial and axial cutting edge position causes approximately 50% of the force variation for the case studied in this paper. Approximately 40% arises from eccentricity and the remaining 10% is the result of spindle deflection during machining. The experimental results presented in this paper show a new type of cutting force diagrams where the force variation for each individual tooth when two cutting edges are engaged in the workpiece at the same time. The wear studies performed shows a redistribution of the individual main cutting forces dependent on the wear propagation for each tooth.
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| 5. |
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| 6. |
- Andersson Lundell, Anna-Carin, 1976, et al.
(författare)
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Development of gut-homing receptors on circulating B cells during infancy.
- 2011
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Ingår i: Clinical immunology. - : Elsevier BV. - 1521-7035 .- 1521-6616. ; 138:1, s. 97-106
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Tidskriftsartikel (refereegranskat)abstract
- B cell gut-homing is mainly mediated by α4β7, CCR9 and CCR10. We here studied the expression of these receptors on B cells from cord blood and from peripheral blood at 1, 4, 18 and 36months of age in a prospective cohort of Swedish infants. The proportion of all B cells expressing α4β7 as well as the fraction of CCR10+ B cells expressing α4β7 was highest in early infancy. Nearly all naïve B cells in all age groups expressed α4β7, whereas the expression on class-switched B cells decreased with age. Moreover, the proportion of both IgA+ and IgG+ B cells expressing α4β7, CCR9 and CCR10 were higher during the first months when compared to adults. In conclusion, the high fraction of circulating IgA+ and IgG+ B cells expressing CCR9 and CCR10 in the first months of life indicates activation of naïve B cells in the gut, coinciding with bacterial colonization.
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| 7. |
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| 8. |
- Barregård, Lars, 1948, et al.
(författare)
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Experimental exposure to wood smoke: effects on airway inflammation and oxidative stress.
- 2008
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Ingår i: Occupational and environmental medicine. - : BMJ. - 1470-7926 .- 1351-0711. ; 65:5, s. 319-24
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Particulate air pollution affects cardiovascular and pulmonary disease and mortality. A main hypothesis about the mechanisms involved is that particles induce inflammation in lower airways, systemic inflammation and oxidative stress. OBJECTIVES: To examine whether short-term exposure to wood smoke in healthy subjects affects markers of pulmonary inflammation and oxidative stress. METHODS: 13 subjects were exposed first to clean air and then to wood smoke in a chamber during 4-hour sessions, 1 week apart. The mass concentrations of fine particles at wood smoke exposure were 240-280 mug/m(3), and number concentrations were 95 000-180 000/cm(3), about half of the particles being ultrafine (<100 nm). Blood and breath samples were taken before and at various intervals after exposure to wood smoke and clean air and examined for exhaled nitric oxide and Clara cell protein in serum and urine, and malondialdehyde in exhaled breath condensate. RESULTS: Exposure to wood smoke increased alveolar nitric oxide 3 hours post-exposure while malondialdehyde levels in breath condensate were higher both immediately after and 20 hours after exposure. Serum Clara cell protein was increased 20 hours after exposure. CONCLUSIONS: Wood smoke at levels that can be found in smoky indoor environments caused an inflammatory response and signs of increased oxidative stress in the respiratory tract, especially in the lower airways.
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| 9. |
- Bjerg, Anders, et al.
(författare)
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Shorter time to clinical decision in work-related asthma using a digital tool
- 2020
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Ingår i: ERJ open research. - Lausanne, Switzerland : European Respiratory Society (ERS). - 2312-0541. ; 6:3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- PEF curves are a useful but cumbersome tool in diagnosing work-related asthma. Using a digital spirometer and smartphone app, time to clinical decision could be shortened by 6-7 weeks. Physician's time spent analysing PEF data is also shortened.
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| 10. |
- Danielsson, Christian, et al.
(författare)
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Exploration of human, rat, and rabbit embryonic cardiomyocytes suggests K-channel block as a common teratogenic mechanism
- 2013
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Ingår i: Cardiovascular Research. - : Oxford University Press (OUP): Policy B. - 0008-6363 .- 1755-3245. ; 97:1, s. 23-32
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Tidskriftsartikel (refereegranskat)abstract
- Several drugs blocking the rapidly activating potassium (K-r) channel cause malformations (including cardiac defects) and embryonic death in animal teratology studies. In humans, these drugs have an established risk for acquired long-QT syndrome and arrhythmia. Recently, associations between cardiac defects and spontaneous abortions have been reported for drugs widely used in pregnancy (e.g. antidepressants), with long-QT syndrome risk. To investigate whether a common embryonic adverse-effect mechanism exists in the human, rat, and rabbit embryos, we made a comparative study of embryonic cardiomyocytes from all three species. less thanbrgreater than less thanbrgreater thanPatch-clamp and quantitative-mRNA measurements of K-r and slowly activating K (K-s) channels were performed on human, rat, and rabbit primary cardiomyocytes and cardiac samples from different embryo-foetal stages. The K-r channel was present when the heart started to beat in all species, but was, in contrast to human and rabbit, lost in rats in late organogenesis. The specific K-r-channel blocker E-4031 prolonged the action potential in a species- and development-dependent fashion, consistent with the observed K-r-channel expression pattern and reported sensitive periods of developmental toxicity. E-4031 also increased the QT interval and induced 2:1 atrio-ventricular block in multi-electrode array electrographic recordings of rat embryos. The K-s channel was expressed in human and rat throughout the embryo-foetal period but not in rabbit. less thanbrgreater than less thanbrgreater thanThis first comparison of mRNA expression, potassium currents, and action-potential characteristics, with and without a specific K-r-channel blocker in human, rat, and rabbit embryos provides evidence of K-r-channel inhibition as a common mechanism for embryonic malformations and death.
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| 11. |
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| 12. |
- Olin, Anna-Carin, 1960, et al.
(författare)
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Prevalence of asthma and exhaled nitric oxide are increased in bleachery workers exposed to ozone.
- 2004
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Ingår i: The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. - 0903-1936. ; 23:1, s. 87-92
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Tidskriftsartikel (refereegranskat)abstract
- The aims of the present study were to determine whether exposure to high peaks of ozone resulted in an increased prevalence of asthma or respiratory symptoms among bleachery workers and whether nitric oxide (NO) was elevated in the exhaled air of these workers. Bleachery workers (n=228) from three Swedish pulp mills who had been exposed to ozone, together with 63 unexposed control subjects, were investigated by means of spirometry, Phadiatop, exhaled and nasal NO and answers to a questionnaire concerning respiratory symptoms and exposure. Exposure to an ozone peak that gave rise to respiratory symptoms was defined as a "gassing". Bleachery workers reporting four or more gassings involving ozone had an increased prevalence of adult-onset asthma, wheeze, and current asthma symptoms. They also had a higher median concentration of exhaled NO in comparison with those who reported no such gassings (19.2 versus 15.7 parts per billion). No such associations were found in respect of nasal NO. The results from this study show that bleachery workers who have been repeatedly exposed to ozone gassings have an increased prevalence of adult-onset asthma. The results also indicate exhaled nitric oxide may be a marker of airway inflammation in bleachery workers who have been exposed to high peaks of ozone.
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| 13. |
- Strömbeck, Anna, et al.
(författare)
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Allergic disease in 8-year old children is preceded by delayed B-cell maturation.
- 2017
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Ingår i: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology. - : Wiley. - 1365-2222. ; 47:7, s. 918-928
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Tidskriftsartikel (refereegranskat)abstract
- We previously reported that exposure to a farming environment is allergy-protective, while high proportions of neonatal immature/naïve CD5(+) B cells and putative regulatory T cells (Tregs) are risk factors for development of allergic disease and sensitization up to 3 years of age.To examine if B- and T-cell maturation are associated with allergic disease and farming environment over the first 8 years in life.In the prospective FARMFLORA study, including both farming and non-farming families, 48 out of 65 children took part in the 8-year follow-up study. Various B- and T-cell maturation variables were examined in blood samples obtained at several occasions from birth to 8 years of age and related to doctors' diagnosed allergic disease and sensitization, and to farming environment.We found that the incidence of allergic disease was lower among farmers' compared to non-farmers' children during the 8-years follow-up period, and that farmers' children had higher proportions of memory B cells at 8 years of age. Moreover, a high proportion of neonatal CD5(+) B cells was a risk factor for and may predict development of allergic disease at 8 years of age. A high proportion of Tregs was not protective against development of these conditions.High proportions of neonatal naïve B cells remained as a risk factor for allergic disease in school-aged children. Thus, the accelerated B-cell maturation observed among farmers' children may be crucial for the allergy-protective effect of a farming environment. This article is protected by copyright. All rights reserved.
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| 14. |
- Abrahamson, Alexandra, et al.
(författare)
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Gill EROD in monitoring of CYP1A inducers in fish : A study in rainbow trout (Oncorhynchus mykiss) caged in Stockholm and Uppsala waters
- 2007
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 85:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was evaluated as a monitoring tool for waterborne cytochrome P4501 A (CYP1A) inducers using rainbow trout (Oncorhynchus mykiss) caged in urban area waters in Sweden. To compare the CYP1A induction response in different tissues, EROD activity was also analyzed in liver and kidney microsomes. Immunohistochemistry was used to localize CYP1A protein in gill and kidney. In two separate experiments fish were caged at sites with fairly high expected polyaromatic hydrocarbon (PAH) contamination. In the first experiment, gill EROD activities were analyzed in fish exposed for 1-21 days in a river running through Uppsala. The reference site was upstream of Uppsala. In the second, gill, liver and kidney EROD activities were analyzed in fish exposed for 1-5 days in fresh or brackish waters of Stockholm and in a reference lake 60 km north of Stockholm. Fish exposed for 5 days followed by 2 days of recovery in tap water in the laboratory were also examined. The gill consistently showed a higher EROD induction compared with the liver and the kidney. After I day of caging, gill EROD activity was markedly induced (6-17-fold) at all sites examined. Induction in gill was pronounced (5-7-fold) also in fish caged at the reference sites. In the 21-day exposure study gill EROD activity remained highly induced throughout the experiment (26-fold at most) and the induced CYP1A protein was exclusively confined to the gill secondary lamellae. In the 5-day exposure experiment, EROD activity peaked after I day and then declined in both gill and liver, while CYP1A immunostaining in the gill remained intense over the 5-day period. In the kidney, CYP1A staining was weak or absent. We conclude that gill EROD activity is a more sensitive biomarker of exposure to waterborne CYP1A inducers than EROD activity in liver and kidney.
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| 15. |
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| 16. |
- Ahadi, Aylin, et al.
(författare)
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Increased examination frequency and learning for a large group of students early in their education
- 2005
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Konferensbidrag (refereegranskat)abstract
- Abstract—Denna artikel beskriver hur undervisningen i grundkursen i mekanik för maskinteknik förändrades för att främja djupinlärning hos studenterna och öka examinationsfrekvensen. Strategin var baserad på utökade möjligheter för aktiv inlärning och styrning av inlärning genom att införa förändringar i examinationen. Under kursens gång implementerades kontinuerlig examination med inlämningsuppgifter och två deltentamina där kursboken och en ordlista med viktiga begrepp kunde användas som hjälpmedel. Resultaten visade en signifikant ökning av examinationsfrekvensen och även en ökning av studenternas motivation och engagemang i kursen jämfört med tidigare år. Pedagogiska aktiviteter som en introduktionsföreläsning, muntlig problempresentation och kamratgranskning skulle kunna skapa ännu bättre förutsättningar för djupinlärning
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| 17. |
- Ahlskog, Mats, 1970-
(författare)
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Supporting pre-development of new manufacturing technologies
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In today’s tough industrial environment, efficient development of new products and new manufacturing solutions is necessary to stay competitive on a global market. Manufacturing companies use substantial money and development resources to develop new products. However, the resources spent on finding and implementing emerging manufacturing technologies are much more limited. This is often the case even though it is well known that a way of competing on a global market is through the introduction of new manufacturing technologies that can improve product quality as well as contribute to reducing manufacturing time, resulting in reduced product price and in the end increased profit.When introducing new manufacturing technologies, different challenges arise such as lack of knowledge, involvement of an external equipment supplier, etc. In addition, time-to-volume is critical when introducing new manufacturing technologies in a manufacturing context. To be able to have a fast ramp-up, manufacturing technology needs to be mature enough and at the same time meet all requirements. Efficient introduction of new manufacturing technologies requires that pre-development activities have been performed in advance.Previous research in this area highlights a lack of knowledge and solutions regarding pre-development of new manufacturing technologies. Such pre-development is important in order to have a successful introduction, fast time-to-volume and production system development. Based on these challenges, the objective of the research presented in this thesis is to develop support for pre-development of new manufacturing technologies.The research is based on literature reviews and three empirical case studies, carried out over a two-year period of time. The first empirical case study was an exploratory case study in the manufacturing industry. The purpose of that research study was to identify critical factors forcing manufacturing companies to improve the development of manufacturing technologies.The second study was a longitudinal embedded case study in the manufacturing industry with the purpose of identifying factors that affect evaluation of new manufacturing technologies during new product development. Particular attention was given to the product development process and how it has affected the evaluation of new manufacturing technologies.Finally, the third study was a single case study in the manufacturing industry with the purpose of analysing and discussing the assessment of the maturity level of a manufacturing technology.
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| 18. |
- Aldridge, Jonathan, et al.
(författare)
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Blood chemokine levels are markers of disease activity but not predictors of remission in early rheumatoid arthritis.
- 2022
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Ingår i: Clinical and experimental rheumatology. - : Clinical and Experimental Rheumatology. - 0392-856X .- 1593-098X. ; 40:7, s. 1393-1402
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Tidskriftsartikel (refereegranskat)abstract
- In early rheumatoid arthritis (eRA) plasma levels of specific chemokines have been shown to correlate with disease activity. However, it is unclear whether pre-treatment chemokine levels can predict disease remission at week 24, and it is not known how biological treatments with different modes of action affect plasma chemokine levels in patients with untreated eRA.This study included 347 Swedish patients with untreated eRA from the larger NORD-STAR randomised treatment trial. Here, eRA patients were treated with methotrexate combined with either prednisolone, anti-TNF (certolizumab-pegol), CTLA-4Ig (abatacept) or anti-IL6 receptor (tocilizumab). The primary clinical outcome was remission by clinical disease activity index (CDAI) defined as CDAI ≤ 2.8. Disease activity was assessed by CDAI, DAS28-ESR, DAS28-CRP, swollen joint counts, tender joint counts, ESR and CRP. The plasma concentrations of 14 chemokines were measured at baseline and after 24 weeks of treatment by bead-based immunoassay or ELISA.Baseline plasma concentrations of CXCL10, CXCL8, CXCL9, CXCL11, CXCL5 and CCL2 correlated with baseline disease activity measures. After 24 weeks of treatment, plasma levels of CXCL10, CXCL8, CXCL9, CXCL11 and CXCL13 decreased in all treatment groups except in patients treated with anti-IL6 receptor. In multivariate factor analysis, plasma chemokine levels at baseline could not differentiate patients who attained remission by week 24 from those who did not in any of the treatment groups.In patients with untreated eRA, plasma levels of several chemokines correlate with disease activity at baseline but cannot predict remission after 24 weeks of treatment with methotrexate combined with prednisolone, anti‑TNF, CTLA‑4Ig or anti‑IL6R.
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| 19. |
- Aldridge, Jonathan, et al.
(författare)
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Blood PD-1+TFh and CTLA-4+CD4+ T cells predict remission after CTLA-4Ig treatment in early rheumatoid arthritis.
- 2022
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Ingår i: Rheumatology (Oxford, England). - : Oxford University Press (OUP). - 1462-0324 .- 1462-0332. ; 61:3, s. 1233-1242
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Tidskriftsartikel (refereegranskat)abstract
- Treatment with CTLA-4Ig blocks T cell activation and is clinically effective in rheumatoid arthritis (RA). However, it is unknown if specific CD4+ T cell subsets in blood at baseline predict remission after CTLA-4Ig, or other biological treatments with different modes of action, and how treatment affects CD4+ T cells in patients with untreated early RA (eRA).This study included 60 patients with untreated eRA from a larger randomised trial. They were treated with methotrexate combined with CTLA-4Ig (abatacept, n=17), anti-IL6 receptor (tocilizumab, n=21) or anti-TNF (certolizumab-pegol, n=22). Disease activity was assessed by clinical disease activity index (CDAI), DAS28, swollen joint counts, tender joint counts, CRP and ESR. The primary outcome was CDAI remission (CDAI≤2.8) at week 24. Proportions of 12 CD4+ T cell subsets were measured by flow cytometry at baseline and after 4, 12 and 24weeks of treatment.In patients treated with CTLA-4Ig, the proportions of PD-1+TFh and CTLA-4+ conventional CD4+ T cells at baseline predicted CDAI remission at week 24. CD4+ T cell subset proportions could not predict remission after treatment with anti-IL6R or anti-TNF. The percentage of regulatory T cells (Tregs) expressing CTLA-4 decreased in all treatment arms by 24weeks, but only CTLA-4Ig treatment significantly reduced the proportions of Tregs and PD-1+T follicular helper (TFh) cells.These findings indicate that circulating proportions PD-1+TFh and CTLA-4+ conventional CD4+ T cells at baseline may serve as predictive biomarkers for remission in early RA after CTLA-4Ig treatment.
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| 20. |
- Aldridge, Jonathan, et al.
(författare)
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Sex-based differences in association between circulating T cell subsets and disease activity in untreated early rheumatoid arthritis patients
- 2018
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Ingår i: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6354 .- 1478-6362. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is not known if sex-based disparities in immunological factors contribute to the disease process in rheumatoid arthritis (RA). Hence, we examined whether circulating T cell subset proportions and their association with disease activity differed in male and female patients with untreated early rheumatoid arthritis (ueRA). Methods: Proportions of T cell subsets were analyzed in peripheral blood from 72 ueRA DMARD-and corticosteroid-naive patients (50 females and 22 males) and in 31 healthy age-and sex-matched controls. Broad analysis of helper and regulatory CD4(+) T cell subsets was done using flow cytometry. Disease activity in patients was assessed using DAS28, CDAI, swollen joint counts, tender joint counts, CRP, and ESR. Results: Multivariate factor analyses showed that male and female ueRA patients display distinct profiles of association between disease activity and circulating T cell subset proportions. In male, but not female, ueRA patients Th2 cells showed a positive association with disease activity and correlated significantly with DAS28-ESR, CDAI, and swollen and tender joint counts. Likewise, proportions of non-regulatory CTLA-4(+) T cells associated positively with disease activity in male patients only, and correlated with DAS28-ESR. In contrast, there was a negative relation between Th1Th17 subset proportions and disease activity in males only. The proportions of Th17 cells correlated positively with DAS28-ESR in males only, while proportions of Th1 cells showed no relation to disease activity in either sex. There were no significant differences in proportions of T cell subsets between the sexes in patients with ueRA. Conclusions: Our findings show sex-based differences in the association between T cell subsets and disease activity in ueRA patients, and that Th2 helper T cells may have a role in regulating disease activity in male patients.
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| 21. |
- Aldridge, Jonathan, et al.
(författare)
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T helper cells in synovial fluid of patients with rheumatoid arthritis primarily have a Th1 and a CXCR3(+)Th2 phenotype
- 2020
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Ingår i: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6354 .- 1478-6362. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The majority of CD4(+)T helper (Th) cells found in the synovial fluid (SF) of patients with rheumatoid arthritis (RA) express CXCR3, a receptor associated with Th1 cells. In blood, subsets of Th2 and Th17 cells also express CXCR3, but it is unknown if these cells are present in RA SF or how cytokines from these subsets affect cytokine/chemokine secretion by fibroblast-like synoviocytes (FLS) from patients with RA. Methods We examined the proportions of Th1, Th2, CXCR3(+)Th2, Th17, CXCR3(+)Th17, Th1Th17, peripheral T helper (TPh) and T follicular helper (TFh) cells in paired SF and blood, as well as the phenotype of TPh and TFh cells in RA SF (n = 8), by the use of flow cytometry. We also examined the cytokine/chemokine profile in paired SF and plasma (n = 8) and in culture supernatants of FLS from patients with chronic RA (n = 7) stimulated with Th-associated cytokines, by the use of cytometric bead arrays and ELISA. Cytokine receptor expression in FLS (n = 3) were assessed by the use of RNA sequencing and qPCR. Results The proportions of Th1 and CXCR3(+)Th2 cells were higher in SF than in blood (P < 0.05). TPh and PD-1(high)TFh in RA SF were primarily of a Th1 and a CXCR3(+)Th2 phenotype. Moreover, the levels of CXCL9, CXCL10, CCL20, CCL2, CXCL8, IL-6 and IL-10 were higher in SF than in plasma (P < 0.05). Lastly, IL-4, IL-13 and IL-17A induced RA FLS to secrete proinflammatory IL-6, CCL2, CXCL1 and CXCL8, while IFN gamma mainly induced CXCL10. Conclusion These findings indicate that not only Th1 but also CXCR3(+)Th2 cells may have a pathogenic role in RA synovial inflammation.
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| 22. |
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| 23. |
- Almström, Peter, 1972, et al.
(författare)
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Achieving Sustainable Production through Increased Utilization of Production Resources
- 2011
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Ingår i: Proceedings of the 4th Swedish Production Symposium, SPS11, Lund, May 3-5, 2011. ; , s. 398-406
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Konferensbidrag (refereegranskat)abstract
- There seems to be a quite divergent view on sustainable production, mainly based on the perspective applied. From a global perspective, every kind of material consumption and growth is basically unwanted and should be minimized. This reflects in economic sustainability parameters that point towards producing as little as possible and socialparameters pointing at eliminating abuse of human rights etc. On the other hand, international summits on sustainability have stated that it is a human right to have a certain standard of living, which implies increase in production but with less resource consumption. This global perspective is however not very helpful when focusing on more local level, for example Swedish manufacturing industry. To achieve a long-term jobsecurity the manufacturing companies need to be long-term prosperous. Further, to be able to maintain profitability levels, manufacturing companies need to continuouslyincrease productivity. Utilization deals with using production equipment in a cost efficient way and this article will highlight how utilization affects different aspects of sustainable production, the link between utilization and productivity, as well as practical considerations when improving utilization in manufacturing industry.
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| 24. |
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| 25. |
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| 26. |
- Andersson, Anna-Carin, 1976, et al.
(författare)
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Activation of human neonatal monocyte-derived dendritic cells by lipopolysaccharide down-regulates birch allergen-induced Th2 differentiation
- 2004
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Ingår i: Eur J Immunol. ; 34:12, s. 3516-24
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological studies describe an inverse association between the level of environmental endotoxin exposure during infancy and the prevalence of allergic disease in children. To study the effect of lipopolysaccharide (LPS) and lipopeptide Pam3Cys signaling via Toll-like receptor (TLR)4 and TLR2 on dendritic cells (DC), respectively, on birch allergen-induced T cell differentiation, cord blood monocyte-derived DC were exposed to birch allergen extract alone or in combination with LPS or Pam3Cys and thereafter co-cultured with naive autologous T cells. We demonstrate that birch allergen alone induced high levels of IL-13 from neonatal T cells, whereas the production of IL-5 and IFN-gamma was modest. Stimulation of DC with birch allergen together with LPS but not Pam3Cys resulted in a decreased IL-13 production by T cells compared to birch allergen alone. Furthermore, birch allergen together with LPS induced increased up-regulation of activation markers expressed on the surface and production of cytokines from DC relative to stimulation with birch allergen alone. Finally, birch allergen partially suppressed both LPS- and Pam3Cys-induced DC maturation. Our results indicate that concomitant TLR4 stimulation during the initial phase of immune activation to birch allergen in infants may inhibit the development of a T helper 2-type response.
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| 27. |
- Andersson, Anna-Carin, 1962
(författare)
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Agent A med licens att tolka förhistorien
- 1999
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Ingår i: Anders Gustafsson och Håkan Karlsson (red.) Glyfer och arkeologiska rum - en vänbok till Jarl Nordbladh, GOTARC Series A, Vol 3.. - Göteborg : University of Gothenburg. - 9185952214 ; , s. 351-373
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
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| 28. |
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| 29. |
- Andersson, Anna-Carin, 1962
(författare)
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Bourdieu och Arkeologi. Struktur och praxis bland gropkeramiker på Västerbjers, Gotland
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- With point of departure in three main objectives the purpose of the thesis is to examine the potential of the reasoning and concepts of the French sociologist Pierre Bourdieu (1930–2002) in an analysis of an archaeological material. Earlier attempts to use his reasoning in archaeology have not in a sufficient way considered the complexity of these reasoning. The thesis presents an attempt to adapt and convey these reasoning to enable an archaeological analysis and interpretations about social structure and practice of the Middle-Neolithic Pitted Ware Culture (PWC) as these matters comes to expression within the burial site at Västerbjers, Gothem parish, Gotland. By examining the potential and the sustainability of Bourdieu’s epistemology and theoretical concepts on an archaeological material, the aim of the thesis is on a specific level to achieve a developed knowledge and understanding of the structure and practices such as these may have been constituted at the PWC site of Västerbjers, Gotland. . On a general level, the aim of this study is to contribute to a development of the methodological resources of the archaeological discipline. The results are presented in a summarizing compilation of the compositions of symbolic capital of how individuals group together in different sectors of practice, and how these individuals relate to the general group structure among people of Västerbjers. It is concluded that: Bourdieu’s reasoning, when they are adapted to fit the archaeological context, enables an achievement of qualified understanding concerning society, groups and individual identity and thereby a possibility to visualize intangible, immaterial relationships. This kind of implementation of an adjustment of Bourdieu’s concepts on an archaeological material constitutes a pilot study. The argumentation in this thesis therefore has a more discursive and reflexive character, as no earlier methodological model have been available that could be applied. The outline of the thesis is divided into six parts (part I – VI) with an English summary.
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| 30. |
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| 31. |
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| 32. |
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| 33. |
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| 34. |
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| 35. |
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| 36. |
- Andersson, Anna-Carin, et al.
(författare)
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No apparent reduction of gene flow in a hybrid zone between the West and North European karyotypic groups of the common shrew, Sorex araneus.
- 2004
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Ingår i: Mol Ecol. - 0962-1083. ; 13:5, s. 1205-15
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Tidskriftsartikel (refereegranskat)abstract
- The common shrew, Sorex araneus, exhibits an unusually high level of karyotypic variation. Populations with identical or similar karyotypes are defined as chromosome races, which are, in turn, grouped into larger evolutionary units, karyotypic groups. Using six microsatellite markers, we investigated the genetic structure of a hybrid zone between the Sidensjo and Abisko chromosome races, representatives of two distinct karyotypic groups believed to have been separated during the last glacial maximum, the West European karyotypic group (western group) and the North European karyotypic group (northern group), respectively. Significant FST values among populations suggest some weak genetic structure. All hierarchical levels show similar levels of genetic differentiation, equivalent to levels of genetic structure in several intraracial studies of common shrew populations from central Europe. Notably, genetic differentiation was of the same order of magnitude between and within karyotypic groups. Although the genetic differentiation was weak, the correlation between genetic and geographical distance was positive and significant, suggesting that the genetic variation observed between populations is a function of geographical distance rather than racial origin. Hence, considerable chromosomal differences do not seem to prevent extensive gene flow.
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| 37. |
- Andersson, Anna-Carin, 1970-
(författare)
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Postglacial Population History of the Common Shrew (Sorex araneus) in Fennoscandia : Molekylära studier av återkolonisation, könsbundet genflöde och kromosomrasbildning.
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The common shrew, Sorex araneus, has one of the most variable karyotypes among mammals, displaying numerous chromosomes races throughout its distribution, which can be categorized into different karyotypic groups. The objective of this thesis was to examine the postglacial population history of Fennoscandian common shrews using autosomal microsatellites, mitochondrial DNA (mtDNA) and a Y chromosome specific microsatellite (L8Y).Autosomal microsatellites and mtDNA revealed weak genetic structure over a hybrid zone between the karyotypically divergent Northern and Western karyotypic groups. However, the genetic structure displayed by the Y chromosome microsatellite was orders of magnitude higher. Hence, considerable chromosomal differences between the groups do not prevent female gene flow, while male gene flow is reduced (cf. Haldane's rule). Further, the results suggest that the Haldane effect may be caused by the chromosomal differences between the karyotypic groups.No mtDNA differentiation was observed either between chromosome races or between the Northern and Western karyotypic groups in Fennoscandia. The combined pattern of karyotypic and mtDNA variation of Fennoscandian common shrews, suggest bi-directional postglacial recolonisation from a single refugium in Europe. The variation of the Y-linked microsatellite supported this conclusion. In contrast, significant mtDNA structure, discordant with the karyotypic variation, revealed that common shrews in southern Finland belong to a different lineage than remaining Fennoscandian regions, implying postglacial recolonisation from a different source.MtDNA variation of the chromosome races in Sweden supports the hypothesis that three races of the Western karyotypic group have been formed through whole arm reciprocal translocations (WARTs), as suggested by their mutual karyotypic variation. The variation of the molecular markers supports the theory of rapid karyotypic evolution in the common shrew.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
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| 42. |
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| 43. |
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| 44. |
- Andersson, Anna, et al.
(författare)
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Gene expression profiling of leukemic cell lines reveals conserved molecular signatures among subtypes with specific genetic aberrations
- 2005
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 19:6, s. 1042-1050
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Tidskriftsartikel (refereegranskat)abstract
- Hematologic malignancies are characterized by fusion genes of biological/clinical importance. Immortalized cell lines with such aberrations are today widely used to model different aspects of leukemogenesis. Using cDNA microarrays, we determined the gene expression profiles of 40 cell lines as well as of primary leukemias harboring 11q23/MLL rearrangements, t(1;19)[TCF3/PBX1], t(12;21)[ETV6/RUNX1], t(8;21)[RUNX1/CBFA2T1], t(8;14) [IGH@/MYC], t(8;14)[TRA@/MYC], t(9;22)[BCR/ABL1], t(10;11) [PICALM/MLLT10], t(15;17)[PML/RARA], or inv(16)[CBFB/MYH11]. Unsupervised classification revealed that hematopoietic cell lines of diverse origin, but with the same primary genetic changes, segregated together, suggesting that pathogenetically important regulatory networks remain conserved despite numerous passages. Moreover, primary leukemias cosegregated with cell lines carrying identical genetic rearrangements, further supporting that critical regulatory pathways remain intact in hematopoietic cell lines. Transcriptional signatures correlating with clinical subtypes/primary genetic changes were identified and annotated based on their biological/molecular properties and chromosomal localization. Furthermore, the expression profile of tyrosine kinase-encoding genes was investigated, identifying several differentially expressed members, segregating with primary genetic changes, which may be targeted with tyrosine kinase inhibitors. The identified conserved signatures are likely to reflect regulatory networks of importance for the transforming abilities of the primary genetic changes and offer important pathogenetic insights as well as a number of targets for future rational drug design.
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| 45. |
- Andersson, Anna, et al.
(författare)
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Microarray-based classification of a consecutive series of 121 childhood acute leukemias: prediction of leukemic and genetic subtype as well as of minimal residual disease status.
- 2007
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 21:6, s. 1198-1203
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Tidskriftsartikel (refereegranskat)abstract
- Gene expression analyses were performed on 121 consecutive childhood leukemias (87 B-lineage acute lymphoblastic leukemias (ALLs), 11 T-cell ALLs and 23 acute myeloid leukemias (AMLs)), investigated during an 8-year period at a single center. The supervised learning algorithm k-nearest neighbor was utilized to build gene expression predictors that could classify the ALLs/AMLs according to clinically important subtypes with high accuracy. Validation experiments in an independent data set verified the high prediction accuracies of our classifiers. B-lineage ALLs with uncharacteristic cytogenetic aberrations or with a normal karyotype displayed heterogeneous gene expression profiles, resulting in low prediction accuracies. Minimal residual disease status (MRD) in T-cell ALLs with a high (40.1%) MRD at day 29 could be classified with 100% accuracy already at the time of diagnosis. In pediatric leukemias with uncharacteristic cytogenetic aberrations or with a normal karyotype, unsupervised analysis identified two novel subgroups: one consisting mainly of cases remaining in complete remission (CR) and one containing a few patients in CR and all but one of the patients who relapsed. This study of a consecutive series of childhood leukemias confirms and extends further previous reports demonstrating that global gene expression profiling provides a valuable tool for genetic and clinical classification of childhood leukemias.
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| 46. |
- Andersson, Anna, et al.
(författare)
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Paired multiplex reverse-transcriptase polymerase chain reaction (PMRT-PCR) analysis as a rapid and accurate diagnostic tool for the detection of MLL fusion genes in hematologic malignancies
- 2001
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Ingår i: Leukemia. - 1476-5551. ; 15:8, s. 1293-1293
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Tidskriftsartikel (refereegranskat)abstract
- The MLL gene in chromosome band 11q23 is frequently rearranged in acute lymphoblastic and acute myeloid leukemias. To date, more than 50 different chromosomal regions are known to participate in translocations involving 11q23, many of which affect MLL. The pathogenetically important outcome of these rearrangements is most likely the creation of a fusion gene consisting of the 5' part of the MLL gene and the 3' end of the partner gene. Although abnormalities of the MLL gene as such are generally associated with poor survival, recent data suggest that the prognostic impact varies among the different fusion genes generated. Hence, detection of the specific chimeric gene produced is important for proper prognostication and clinical decision making. We have developed a paired multiplex reverse-transcriptase polymerase chain reaction analysis to facilitate a rapid and accurate detection of the most frequent MLL fusion genes in adult and childhood acute leukemias. To increase the specificity, two sets of primers were designed for each fusion gene, and these paired primer sets were run in parallel in two separate multiplex one-step PCR reactions. Using the described protocol, we were able to amplify successfully, in one single assay, the six clinically relevant fusion genes generated by the t(4;11)(q21;q23) [MLL/AF4], t(6;11)(q27;q23) [MLL/AF6], t(9;11)(p21-22;q23) [MLL/AF9], t(10;11)(p11-13;q23) [MLL/AF10], t(11;19)(q23;p13.1) [MLL/ELL], and t(11;19)(q23; p13.3) [MLL/ENL] in cell lines, as well as in patient material.
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| 47. |
- Andersson, Carin, et al.
(författare)
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A chemometrical approach to study interactions between ethynylestradiol and an AhR-agonist in stickleback (Gasterosteus aculeatus)
- 2010
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Ingår i: Journal of Chemometrics. - : Wiley. - 0886-9383 .- 1099-128X. ; 24:11-12, s. 768-778
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Tidskriftsartikel (refereegranskat)abstract
- Quantifiable responses in fish, such as induction of certain proteins, can be used as indicators of chemical contamination of waterways. In order to evaluate differences in ethoxyresorufin-O-deethylase (EROD) induction capacity of the gill and the liver and effects on organs and biomarker proteins, e.g. gill and liver EROD, hepatosomatic index (HSI), nephrosomatic index (NSI), gonadosomatic index (GSI), spiggin, vitellogenin and sperm motility were analysed in male three-spined sticklebacks (Gasterosteus aculeatus) exposed for 21 days to β-naphthoflavone (βNF) alone (Exp 1) or in combination with 17α-ethynylestradiol (EE2) (Exp 2). The sperm motility variables were studied using computer-assisted sperm analysis (CASA). Exp 1: Gill EROD activity was significantly induced in fish exposed to ≥1.2 µg/l and hepatic EROD activity in fish exposed to ≥6 µg/l. No significant effect of ßNF on the production of spiggin or vitellogenin or on sperm variables was found. Exp 2: A significant additative effect of EE2 + βNF was shown for gill EROD. A significant antagonistic effect of the two compounds was found on NSI where an increased EE2 concentration led to an increase in NSI while an increased concentration of βNF led to a decreased NSI. Interestingly, the results showed that exposure to intermediate concentrations of EE2 and ßNF led to a significant increase in the sperm variables. In the aquatic environment mixtures of numerous chemicals with oestrogenic activity are present, so if the capacity to induce gill EROD activity is a general property of oestrogen-acting chemicals, our findings are important.
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| 48. |
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| 49. |
- Andersson, Carin, et al.
(författare)
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Bandsawing. Part II: detecting positional errors, tool dynamics and wear by cutting force measurement
- 2000
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 237-253
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a method for measuring individual cutting forces during bandsawing. Methods for detecting errors in cutting edge positions, tool dynamics during machining and geometry changes due to wear have also been developed. The experimental studies that we have conducted show that the cutting forces vary during the tool engagement. These variations in force were then quantified using a previously developed cutting force model for multi-tooth cutting processes including effects of positional errors, tool dynamics and wear.
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| 50. |
- Andersson, Carin
(författare)
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Bandsawing. Part III: stress analysis of saw tooth microgeometry
- 2001
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 255-263
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a stress analysis of a saw tooth. The analysis aims to determine the stress distribution for various egde load and varying microgeometry. The analysis is performed on a three-dimensional finite element model representing the tip of a saw tooth. The 3D model makes it possible to model the load distribution and study stress distributions across the width of the teeth with a sufficient accuracy. The FEM calculations are based on experimental measurements of the individual cutting forces during bandsawing. The previous studies of nonuniform contact relationships on the rake face is used when modelling the load distribution.
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