15 research outputs found

    Object search by manipulation

    Get PDF
    We investigate the problem of a robot searching for an object. This requires reasoning about both perception and manipulation: some objects are moved because the target may be hidden behind them, while others are moved because they block the manipulator’s access to other objects. We contribute a formulation of the object search by manipulation problem using visibility and accessibility relations between objects. We also propose a greedy algorithm and show that it is optimal under certain conditions. We propose a second algorithm which takes advantage of the structure of the visibility and accessibility relations between objects to quickly generate plans. Our empirical evaluation strongly suggests that our algorithm is optimal under all conditions. We support this claim with a partial proof. Finally, we demonstrate an implementation of both algorithms on a real robot using a real object detection system

    DNA Sequence Profiles of the Colorectal Cancer Critical Gene Set KRAS-BRAF-PIK3CA-PTEN-TP53 Related to Age at Disease Onset

    Get PDF
    The incidence of colorectal cancer (CRC) increases with age and early onset indicates an increased likelihood for genetic predisposition for this disease. The somatic genetics of tumor development in relation to patient age remains mostly unknown. We have examined the mutation status of five known cancer critical genes in relation to age at diagnosis, and compared the genomic complexity of tumors from young patients without known CRC syndromes with those from elderly patients. Among 181 CRC patients, stratified by microsatellite instability status, DNA sequence changes were identified in KRAS (32%), BRAF (16%), PIK3CA (4%), PTEN (14%) and TP53 (51%). In patients younger than 50 years (n = 45), PIK3CA mutations were not observed and TP53 mutations were more frequent than in the older age groups. The total gene mutation index was lowest in tumors from the youngest patients. In contrast, the genome complexity, assessed as copy number aberrations, was highest in tumors from the youngest patients. A comparable number of tumors from young (<50 years) and old patients (>70 years) was quadruple negative for the four predictive gene markers (KRAS-BRAF-PIK3CA-PTEN); however, 16% of young versus only 1% of the old patients had tumor mutations in PTEN/PIK3CA exclusively. This implies that mutation testing for prediction of EGFR treatment response may be restricted to KRAS and BRAF in elderly (>70 years) patients. Distinct genetic differences found in tumors from young and elderly patients, whom are comparable for known clinical and pathological variables, indicate that young patients have a different genetic risk profile for CRC development than older patients

    Registreringsboken for dekkskadetter og matroslærlinger

    Get PDF
    Tittel for oppgave var ”Registreringsboken for dekkskadetter og matroslærlinger.” Problemstillingene var: 1. ”Hvordan er oppfatningen av Registreringsboken for Dekkskadetter og Matroslærlinger (RDM) i det praktiske liv om bord på offshorefartøyer?” 2. ”Hvordan stiller næringen seg til å erstatte RDM med et nytt elektronisk opplæringsverktøy?” Det ble gjennomført en spørreundersøkelse som rettet seg mot dekkskadetter og opplæringsansvarlige om bord på offshorefartøyer. En sekundærundersøkelse med intervjuer ble gjennomført der man intervjuet representanter fra sjøfartsnæringen. Sjøfartsdirektoratets databaser for D3 sertifikater (sertifikatet man søker om etter fullført opplæring gjennom RDM) i 2011 ble også gjennomgått for å få et overblikk over antall søkere og antall avslag som skyldes RDM. Det ble konkludert med at RDM oppfattes som utdatert på en del punkter, men at den er grei å ha som veiledning i opplæringen. Mange seilende er også av den oppfatning at en del søkere får avslag på søknaden om D3 sertifikat på grunn av misforståelser ved RDM, og at den reelle opplæring oppnås gjennom arbeidsoppgaver og veiledning fra andre om bord. Konklusjonen etter databasesøkene tyder det på at det ikke er spesielt mange som får avslag der RDM er eneste avslagsgrunn. Det kan tenkes at denne oppfatningen henger igjen fra tidligere siden Sjøfartsdirektoratet hevder de var mer rigid i tolkningen av regelverket knyttet til sertifikatsøknader før 2007. Videre stiller flertallet av respondentene og intervjuobjektene seg positive til et nytt elektronisk opplæringsprogram. De mener opplæringen vil bli lettere, og at et elektronisk opplæringsprogram med tettere oppfølging vil kunne redusere antall avslag for førstegangssøkere

    Dominant risk factors for retinopathy at clinical diagnosis in patients with type II diabetes mellitus

    No full text
    A study of 270 newly presenting, previously untreated, type II diabetic patents revealed that 38 patients (14%) had already developed diabetic retinopathy (DR). Among this group, 26 patients had lesions of background diabetic retinopathy and 12 patients already had maculopathy or preproliferative changes. The aim of this study was to determine the risk factors influencing susceptibility to retinopathy, and to provide an accurate predictive value for diabetic retinopathy from a detailed multiple regression analysis that involved 27 demographic variables and the metabolic and hormonal responses during a meal tolerance test (MTT) at presentation. Compared to the nonretinopaths, the retinopaths had higher fasting plasma glucose levels (FPG) (mean ± SD) (13.9 ± 3.1 versus 11.6 ± 3.2 mmol/L, p < 0.001), lower body-mass index values (BMI) (26.1 ± 3.8 versus 29.3 ± 5.0 kg/m2, p < 0.001) and higher plasma urea concentrations (6.0 ± 1.9 versus 5.3 ± 1.2 mmol/L, p 0.05). In contrast, gender and levels of blood pressure and other lipid levels did not influence the prevalence of diabetic retinopathy. A multiple regression formula for the prediction of diabetic retinopathy was derived and then used to categorize patients into high-risk and low-risk groups. The retinopaths also had higher HbA(1c) (p < 0.001), higher plasma glucose area under curve (0-2 h, p < 0.001), lower plasma insulin area under curve (0-22 h, p < 0.001), lower C-peptide area under curve (0-2 h, p < 0.01). They were also leaner (p < 0.001) and older (p < 0.05). However, these variables did not feature significantly in the multiple regression formula. The retinopaths were found to have higher risk probability values (25.1 ± 11.5 versus 13.1 ± 10.4%, p < 0.001). In the high risk group, 81.6% of retinopaths were identified. In the low-risk group, 63.8% of nonretinopaths were found. The incidence of diabetic retinopathy in type II diabetic patients at clinical diagnosis was found to be highly related to the degree of hyperglycemia, body-mass index, and to a lesser extent, renal impairment
    corecore