http://hdl.handle.net/2282/137 Search the Channel search http://teora.hit.no:8443/dspace/simple-search http://hdl.handle.net/2282/442 Title: On the integration of object-based models and field-based models in GIS <br/> <br/>Authors: Kjenstad, Kjell <br/> <br/>Abstract: This paper proposes a common base-model for the classical object-based and field-based conceptual models in GIS. The model, which is called the PGOModel or 'Parameterized Geographic Object Model', is given a formal definition by using the UML modelling language. Within the scope of the paper, it has been shown that the PGOModel encompasses the classical object-based and field-based models. Two extensive examples demonstrate the application of the PGO model. The PGOModel seems ontologically well founded, except for the so-called PGOAtom concept. Sat, 29 Oct 2005 22:58:59 GMT http://hdl.handle.net/2282/441 Title: Senglasiale paleogeografiske rekonstruksjonsmodeller testet på utvalgte områder i Norge <br/> <br/>Authors: Kjenstad, Kjell <br/> <br/>Abstract: Avhandlingen tar for seg prinsipper for rekonstruksjon av senglasiale paleogeografiske forhold med spesiell vekt på rekonstruksjon av havnivå og breoverflate. Disse elementene rekonstrueres ved hjelp av ulike matematiske modeller som kalibreres ved hjelp av tilgjengelig feltinformasjon. Slike modeller kan både benyttes til systematisering av felt informasjon i tid og rom, og til datering av isrecessjonen innenfor et område. Praktisk anvendelse av modellene skjer ved hjelp av datamaskiner, fortrinnsvis med grafisk periferiutstyr til å presentere resultatene på kartform. Det gis korte sammendrag av de enkeltartiklene som inngår i avhandlingen. <br/> <br/>Description: Avhandling (dr. scient.) - Universitetet i Oslo, 1984. Sat, 29 Oct 1983 22:58:59 GMT http://hdl.handle.net/2282/434 Title: Association between cigarette smoking, APC mutations and the risk of developing sporadic colorectal adenomas and carcinomas <br/> <br/>Authors: Sæbø, Mona; Skjelbred, Camilla Furu; Breistein, Rebecca; Lothe, Inger Marie Bowitz; Hagen, Per Chr.; Bock, Günther; Hansteen, Inger-Lise; Kure, Elin H. <br/> <br/>Abstract: BACKGROUND: The association between colorectal cancer (CRC) and smoking has not been consistent. Incomplete smoking history and association to a specific subset of CRC tumors have been proposed as explanations. The adenomatous polyposis coli (APC) gene has been reported to have a "gatekeeper" function in the colonic mucosa. METHODS: To evaluate the hypothesis that cigarette smoking is associated with adenoma and carcinoma development and further to investigate whether this association is due to mutations in the APC gene, we used a study population consisting of 133 cases (45 adenomas and 88 carcinomas) and 334 controls. All tumors were sequenced in the mutation cluster region (MCR) of the APC gene. Cases and controls were drawn from a homogeneous cohort of Norwegian origin. RESULTS: The mutational spectra of the APC gene revealed no difference in frequencies of mutations in cases based on ever and never smoking status. An overall case-control association was detected for adenomas and "ever smoking" OR = 1.73 (95% CI 0.83-3.58). For CRC cases several smoking parameters for dose and duration were used. We detected an association for all smoking parameters and "duration of smoking > 30 years", yielded a statistically significant OR = 2.86 (1.06-7.7). When cases were divided based on APC truncation mutation status, an association was detected in adenomas without APC mutation in relation to "ever smoking", with an OR = 3.97 (1.26-12.51). For CRC cases without APC mutation "duration of smoking > 30 years", yielded a statistically significant OR = 4.06 (1.20-13.7). The smoking parameter "starting smoking > or = 40 years ago" was only associated with CRC cases with APC mutations, OR = 2.0 (0.34-11.95). A case-case comparison revealed similar findings for this parameter, OR = 2.24 (0.73-6.86). CONCLUSION: Our data suggest an association between smoking and adenoma and CRC development. This association was strongest for cases without APC truncation mutation. This may implicate other factors in development of these tumors. The association detected between smoking and CRC cases with APC mutation was in relationship to the smoking parameter "starting smoking > or = 40 years ago", a time period long enough to proceed CRC initiation. Sat, 29 Oct 2005 22:58:59 GMT http://hdl.handle.net/2282/433 Title: GPX Pro198Leu and OGG1 Ser326Cys polymorphisms and risk of development of colorectal adenomas and colorectal cancer <br/> <br/>Authors: Hansen, Rikke; Sæbø, Mona; Skjelbred, Camilla Furu; Nexø, Bjørn Andersen; Hagen, Per Chr.; Bock, Günther; Lothe, Inger Marie Bowitz; Johnson, Egil; Aase, Steinar; Hansteen, Inger-Lise; Vogel, Ulla; Kure, Elin H. <br/> <br/>Abstract: Little is known about genetic risk factors for colorectal cancer. We assessed the association between polymorphisms in two genes involved in DNA repair of oxidative stress, GPX and OGG1, and risk of colorectal carcinoma or adenomas. We studied 166 cases with adenocarcinoma, 974 with adenomas and 397 controls recruited from the Norwegian cohort NORCCAP. No associations were found between the polymorphism GPX Pro198Leu and risk of colorectal adenomas or carcinomas. Carriers of the variant allele OGG1 Ser326Cys polymorphism had a lowered risk of colorectal cancer, OR=0.56 (95% confidence interval 0.33-0.95), while no association were found with risk of adenomas. This indicates that a low repair capacity of oxidative DNA damage may not be a risk factor for development of colorectal adenomas or carcinoma. Fri, 29 Oct 2004 22:58:59 GMT