Conformal mapping methods for interfacial dynamics

The article provides a pedagogical review aimed at graduate students in materials science, physics, and applied mathematics, focusing on recent developments in the subject. Following a brief summary of concepts from complex analysis, the article begins with an overview of continuous conformal-map dynamics. This includes problems of interfacial motion driven by harmonic fields (such as viscous fingering and void electromigration), bi-harmonic fields (such as viscous sintering and elastic pore evolution), and non-harmonic, conformally invariant fields (such as growth by advection-diffusion and electro-deposition). The second part of the article is devoted to iterated conformal maps for analogous problems in stochastic interfacial dynamics (such as diffusion-limited aggregation, dielectric breakdown, brittle fracture, and advection-diffusion-limited aggregation). The third part notes that all of these models can be extended to curved surfaces by an auxilliary conformal mapping from the complex plane, such as stereographic projection to a sphere. The article concludes with an outlook for further research.Comment: 37 pages, 12 (mostly color) figure

Tamoxifen and risk of contralateral breast cancer for BRCA1 and BRCA2 mutation carriers

Purpose To determine whether adjuvant tamoxifen treatment for breast cancer (BC) is associated with reduced contralateral breast cancer (CBC) risk for BRCA1 and/or BRCA2 mutation carriers. Methods Analysis of pooled observational cohort data, self-reported at enrollment and at follow-up from the International BRCA1, and BRCA2 Carrier Cohort Study, Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer, and Breast Cancer Family Registry. Eligible women were BRCA1 and BRCA2 mutation carriers diagnosed with unilateral BC since 1970 and no other invasive cancer or tamoxifen use before first BC. Hazard ratios (HRs) for CBC associated with tamoxifen use were estimated using Cox regression, adjusting for year and age of diagnosis, country, and bilateral oophorectomy and censoring at contralateral mastectomy, death, or loss to follow-up. Results Of 1,583 BRCA1 and 881 BRCA2 mutation carriers, 383 (24%) and 454 (52%), respectively, took tamoxifen after first BC d

Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus

A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10-20), ER-negative BC (P=1.1 × 10-13), BRCA1-associated BC (P=7.7 × 10-16) and triple negative BC (P-diff=2 × 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10-3) and ABHD8 (P<2 × 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3′-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk

Native insect flower visitor diversity and feral honeybees on jarrah (Eucalyptus marginata) in Kings Park, an urban bushland remnant

This study aims to determine firstly the diversity of native insect visitors to flowers on the mass-flowering canopy tree jarrah (Eucalyptus marginata), and secondly the relative abundance of feral honeybees and native insects visiting jarrah flowers. Flower density and nectar production were measured, and observations of animals visiting flowers were made during peak flowering of jarrah in Kings Park. Insects were the most commonly observed floral visitor; 83 species from 63 genera in 38 families across 5 orders were recorded. The overall richness and abundance of insect species visiting jarrah flowers changed through the day. Feral honey bees were by far the most common visitor, accounting for 47 % of observations, and suggesting they are a significant pollinator of jarrah in Kings Park. However, the presence of a number of exclusively nectar- and pollen-feeding native bees and flies, and native anthophilous tiphid wasps and beetles, suggests that the native fauna is still effecting some pollination. The diversity of insects observed visiting jarrah flowers is higher than reported for other eucalypts throughout Australia, and confirms that remnants like Kings Park are significant for the conservation of biodiversity

Record error and range contraction, real and imagined, in the restricted shrub Banksia hookeriana in south-western Australia

Banksia hookeriana Meissn. (Proteaceae) is a fire-killed shrub endemic to the northern sandplains of south-western Australia that could be described as endangered based on its small geographical range (< 5000 km2) and area of occupancy (∼500 km2). Impacts on the species' geographical range by land clearance for farming and mining, and by altered fire regime, were investigated using three lines of evidence: records of herbarium collections, a comprehensive field survey of extant populations, and air photo and satellite images revealing the recent history of land clearance and fires. These show that the species' range has contracted by up to 40% in area and 26% latitudinally through the loss of outlier and range limit populations since 1960. In addition, 22% of remaining native shrubland on the Eneabba sandplain has been lost over this period through clearing for farming and mining, representing further habitat loss for B. hookeriana. Detailed investigation of B. hookeriana herbarium collections (n = 46) revealed important errors that artificially affected the geographical range of the species and emphasized the importance of close examination of all data captured from collection records. Recorded locations occurred hundreds of kilometres outside the current geographical range of the species in areas with different climate and substrate. Incorrect species identification of herbarium specimens further extended the apparent geographical range of the species. On the other hand, credible records indicated the loss of the species from localities at the limits of its range. Overall, a disconcertingly high proportion of records contained errors that may be difficult to identify without close examination of the original collections and detailed ground-truthing. Were these records to be used to model climate envelopes, identify potential habitat where the species might occur, or might migrate to either as pests or under climate change scenarios, or to analyse evolutionary or ecological theory (for example) - as is now becoming commonplace - large errors may ensue

Traits related to efficient acquisition and use of phosphorus promote diversification in Proteaceae in phosphorus‐impoverished landscapes

Published online: 22 March 2021Background and aims: Plant species richness increases with declining soil phosphorus (P) availability, especially for Proteaceae in old infertile landscapes. This difference in richness might be attributed to faster diversification in lineages adapted to P-impoverished soils, i.e. species that possess specialised P-acquisition strategies, and have lower leaf P concentration ([P]) and higher seed [P]. Alternatively, a longer time for species accumulation might contribute to high species richness in low-P environments due to the geological stability of the landscapes in which they evolved. Methods: We assessed differences in diversification of Proteaceae in P-impoverished vs. nutrient-rich environments and whether these were linked to adaptations to P-impoverished soils. We explored mature leaf and seed [P] and investigated how these traits changed over the evolutionary history of the family, and within two species-rich genera (Banksia, Hakea). Results: Faster diversification was correlated with lower leaf and higher seed [P] for species-rich genera across the Proteaceae. For Banksia and Hakea, diversification rates peaked at relatively low leaf [P], but not at the lowest leaf [P]. Ancestral state reconstructions indicated that low leaf [P] is a trait that was likely present in the early evolution of the Proteaceae, with recent transitions to higher leaf [P] across several species-poor rainforest genera. Conclusions: Diversification of Proteaceae correlated strongly with P-related traits. In an evolutionary context, functional cluster roots, low leaf [P] and high seed [P] were likely key innovations allowing diversification. Selection for low leaf [P] early in the evolutionary history of Proteaceae pre-adapted ancestors of this family to diversify into oligotrophic environments. We discuss how our findings are likely relevant for understanding diversification dynamics of other plant families that occur in P-impoverished environments.Patrick E. Hayes, Francis J. Nge, Michael D. Cramer, Patrick M. Finnegan, Peili Fu, Stephen D. Hopper ... et al