Relativity as Support for Presentism: A Modest Evidential Argument

Presentism is roughly the view that only the present exists. This view requires an absolute simultaneity relation. The special theory of relativity, however, is highly successful and does not account for absolute simultaneity. This is widely regarded as an evidential threat to presentism. In what follows, I propose a modest evidential argument in support of presentism on the basis of the physical evidence itself. A weak relativity postulate is shown to follow from a weak light-speed postulate. The weak light-speed postulate, in turn, is shown to be more probable on presentism than on its main rival doctrine, eternalism. Specifically, when one accounts for possible worlds in which the space-time metric is Euclidean (+,+,+,+) rather than Lorentzian (-,+,+,+), the empirical evidence turns out to be more probable on presentism than on eternalism. If successful, this argument provides modest evidential support for presentism and against eternalism. However, the support is drawn from an unexpected source: the physical evidence itself

The Students' cotton spinning

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The Kirche Site: A Late Prehistoric Huron Village in the Upper Trent Valley

The Kirche site is an early 16th century Huron village that was excavated as an integral component of an archaeological project investigating late Iroquoian occupations in the upper Trent valley between approximately A.D. 1450 and 1615, by which time the area had been abandonded. This thesis describes the archaeological material recovered during three seasons of testing and excavation at the Kirche site and outlines a number of interpretations concerning the occupation of this village. As a component of a regionally focused project, analysis and interpretation are directed towards elucidating the nature of the occupation at the Kirche village within the context of its local cultural environment and only secondarily within the broader context of late prehistoric and protohistoric occupations in south-central and eastern Ontario. The Kirche village appears to have had a complex history of formation, characterized by the fission and fusion of household groups. It is suggested that many of the villagers immigrated to the upper Trent valley in the late 15th or early 16th century, and that a small number of an indigenous population settled in the village as well. Population movements during the late prehistoric period in south-central and eastern Ontario appear to have been accompanied by increased warfare, the growth of villages through the accretion of additional population segments and internal village complexity. The archaeological record at the Kirche village provides additional evidence for these occurrences.Master of Arts (MA

Relationship between propagule pressure and colonization pressure in invasion ecology: a test with ships' ballast

Increasing empirical evidence indicates the number of released individuals (i.e. propagule pressure) and number of released species (i.e. colonization pressure) are key determinants of the number of species that successfully invade new habitats. In view of these relationships, and the possibility that ships transport whole communities of organisms, we collected 333 ballast water and sediment samples to investigate the relationship between propagule and colonization pressure for a variety of diverse taxonomic groups (diatoms, dinoflagellates and invertebrates). We also reviewed the scientific literature to compare the number of species transported by ships to those reported in nature. Here, we show that even though ships transport nearly entire local communities, a strong relationship between propagule and colonization pressure exists only for dinoflagellates. Our study provides evidence that colonization pressure of invertebrates and diatoms may fluctuate widely irrespective of propagule pressure. We suggest that the lack of correspondence is explained by reduced uptake of invertebrates into the transport vector and the sensitivity of invertebrates and diatoms to selective pressures during transportation. Selection during transportation is initially evident through decreases in propagule pressure, followed by decreased colonization pressure in the most sensitive taxa

Octonions and the two strictly projective tight 5-designs

In addition to the vertices of the regular hexagon and icosahedron, there are precisely two strictly projective tight 5-designs: one constructed from the short vectors of the Leech lattice and the other corresponding to a generalized hexagon structure in the octonion projective plane. This paper describes a new connection between these two strictly projective tight 5-designs -- a common construction using octonions. Certain octonion involutionary matrices act on a three-dimensional octonion vector space to produce the first 5-design and these same matrices act on the octonion projective plane to produce the second 5-design. This result uses the octonion construction of the Leech lattice due to Robert Wilson and provides a new link between the generalized hexagon Gh(2,8) and the Leech lattice.Comment: Accepted version with significant revisions based on reviewer comments. New title and abstract. 12 page

Exploring the experience of residents during the first six months of family medicine residency training

Background: The shift from undergraduate to postgraduate education signals a new phase in a doctor’s training. This study explored the resident’s perspective of how the transition from undergraduate to postgraduate (PGME) training is experienced in a Family Medicine program as they first meet the reality of feeling and having the responsibility as a doctor.Methods: Qualitative methods explored resident experiences using interpretative inquiry through monthly, individual in-depth interviews with five incoming residents during the first six months of training.  Focus groups were also held with residents at various stages of training to gather their reflection about their experience of the first six months. Residents were asked to describe their initial concerns, changes that occurred and the influences they attributed to those changes.Results: Residents do not begin a Family Medicine PGME program knowing what it means to be a Family Physician, but learn what it means to fulfill this role. This process involves adjusting to significant shifts in responsibility in the areas of Knowledge, Practice Management, and Relationships as they become more responsible for care outcomes.Conclusion: This study illuminated the resident perspective of how the transition is experienced. This will assist medical educators to better understand the early training experiences of residents, how these experiences contribute to consolidating their new professional identity, and how to better align teaching strategies with resident learning needs

Tri6 Is a Global Transcription Regulator in the Phytopathogen Fusarium graminearum

In F. graminearum, the transcriptional regulator Tri6 is encoded within the trichothecene gene cluster and regulates genes involved in the biosynthesis of the secondary metabolite deoxynivalenol (DON). The Tri6 protein with its Cys2His2 zinc-finger may also conform to the class of global transcription regulators. This class of global transcriptional regulators mediate various environmental cues and generally responds to the demands of cellular metabolism. To address this issue directly, we sought to find gene targets of Tri6 in F. graminearum grown in optimal nutrient conditions. Chromatin immunoprecipitation followed by Illumina sequencing (ChIP-Seq) revealed that in addition to identifying six genes within the trichothecene gene cluster, Tri1, Tri3, Tri6, Tri7, Tri12 and Tri14, the ChIP-Seq also identified 192 additional targets potentially regulated by Tri6. Functional classification revealed that, among the annotated genes, ∼40% are associated with cellular metabolism and transport and the rest of the target genes fall into the category of signal transduction and gene expression regulation. ChIP-Seq data also revealed Tri6 has the highest affinity toward its own promoter, suggesting that this gene could be subject to self-regulation. Electro mobility shift assays (EMSA) performed on the promoter of Tri6 with purified Tri6 protein identified a minimum binding motif of GTGA repeats as a consensus sequence. Finally, expression profiling of F. graminearum grown under nitrogen-limiting conditions revealed that 49 out of 198 target genes are differentially regulated by Tri6. The identification of potential new targets together with deciphering novel binding sites for Tri6, casts new light into the role of this transcriptional regulator in the overall growth and development of F. graminearum