On the use of repeat leveling for the determination of vertical land motion: artifacts, aliasing and extrapolation errors

Leveling remains the most precise technique for measuring changes in heights. However, for the purposes of determining vertical land motion (VLM), a time series of repeat leveling measurements is susceptible to artifacts and aliasing that may arise due to systematic errors, seasonal surface fluctuations, motions occurring during a survey, and any inconsistencies in the observation conditions among epochs. Using measurements from 10 repeat leveling surveys conducted twice yearly along a profile spanning ~40 km across the Perth Basin, Western Australia, we describe the observation, processing, and analysis methods required to mitigate these potential error sources. We also demonstrate how these issues may lead to misinterpretation of the VLM derived from repeat leveling and may contribute to discrepancies between geologically inferred rates of ground motion or those derived from other geodetic measurement techniques. Finally, we employ historical (~40‐year‐old) leveling data in order to highlight the errors that can arise when attempting to extrapolate VLM derived from a geodetic time series, particularly in cases where the long‐term motion may be nonlinear

Introduction to sustainable agriculture

Previously hosted as part of Mann Library's Locale collection

The UBC Farm : forming market relationships

The goal of this paper is to demonstrate the potential role that the UBC Farm at South Campus has in the UBC Food System. Our group identified two key problems: 1) The UBC Farm’s operating costs exceed its revenue, and 2) UBC food providers have expressed reserved interest in buying UBC Farm produce, but current prices and quantities supplied are not competitive with UBC Food Services current suppliers. We discussed the major constraints preventing the UBC Farm from forming purchasing agreements with UBC Food Services, such as restricted summer availability, quality, and quantity of products. We identified commonalties in our value system, with all group members identifying themselves as weakly anthropocentric. This value identification formed a basis for further exploration of our stated problems. The exploration of Group 14’s representative model of food system sustainability from last year led us to refine it so that it correlated with our own priorities and values. To assess the UBC Farm’s business model, we conducted an examination of each of the components of a business plan. We explored other University and College Farms and compared their strengths and successes to UBC Farm; with these findings we were able to create recommendations to improve the UBC Farm’s profitability in the future. We further emphasize the fact that UBC Farm is limited in food production potential, and has great opportunities for education, research, partnership development, and building social capital. Recommendations for future data collection for next year’s AGSC 450 class include production and economic assessments, market, and case study research. Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”Land and Food Systems, Faculty ofUnreviewedUndergraduat

A 6p22 reference map of leukocyte DNA: exclusion of rearrangement in four cases of atypical haemochromatosis

We describe a 4 Mb reference map of the haemochromatosis gene region in leukocyte DNA from seven controls and four atypical haemochromatosis patients. Three patients had normal coding sequence for HFE, the candidate gene for genetic haemochromatosis (GH). The fourth patient had classical GH but was heterozygous for Cys282Tyr with otherwise normal coding sequence. The genomic DNA was mapped by pulsed-field gel electrophoresis (PFGE) using five rare-cutting enzymes. Seventeen probes including HFE were positioned on the map. Despite proximity to the highly polymorphic major histocompatibility complex (MHC), no polymorphism was observed in the control group with these telomeric probes. Furthermore, major rearrangement of the HFE region was excluded as a mutation contributing to iron overload in these atypical patients. Maps of cloned DNA are linked through genes and other probes to this reference map of the HFE region in uncloned genomic DNA

New polymorphic microsatellite markers place the haemochromatosis gene telomeric to D6S105

The haemochromatosis gene (HFE) is linked to both HLA-A and D6S105 on the short arm of chromosome 6 but these markers are separated by approximately 2 Mb of DNA. Most chromosomes carrying HFE have a common haplotype which extends from HLA-A to D6S105 and includes HLA-F. To localise the gene more precisely we have examined 10 microsatellite markers extending over a genetic distance of approximately 5 cM from D6S265 (within 100 kb of HLA-A on the centromeric side) to D6S299 (telomeric). The order of markers is D6S265, HLA-F, D6S258, D6S306, CS3, D6S105, D6S464, CS5, D6S461 and D6S299. We confirm that haemochromatosis appears to originate from a founder mutation which has multiplied in the population through successive generations. This mutation is associated with the haplotype D6S306-5, CS3-3, D6S105-8, D6S464-9 and CS5-4 which is found on approximately 70% of HFE chromosomes. We have applied a new and powerful, likelihood analysis for linkage disequilibrium. The maximum value of lambda (proportion of total possible association between a marker and disease) is 0.74 for marker CS5 (allele 4). A multipoint analysis also gives a maximum likelihood near marker CS5. We conclude that the HFE gene is likely to be located telomeric of D6S105 and close to CS5