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A flag area measure on a finite-dimensional euclidean vector space is a continuous translation invariant valuation with values in the space of signed measures on the flag manifold consisting of a unit vector $v$ and a $(p + 1)$-dimensional linear subspace containing $v$. Using local parallel sets, Hinderer constructed examples of $SO(n)$- covariant flag area measures. There is an explicit formula for his flag area measures evaluated on polytopes, which involves the squared cosine of the angle between two subspaces. We construct a more general space of $SO(n)$-covariant flag area measures, which satisfy a similar formula for polytopes, but with an arbitrary elementary symmetric polynomial in the squared cosines of the principal angles between two subspaces. Hinderer's flag area measure correspond to the special case where the elementary symmetric polynomial is just the product. We also provide a classification result in the spirit of Hadwiger's theorem. We introduce a natural notion of smoothness and show that every smooth $SO(n)$-covariant flag area measure is a linear combination of the ones which we constructed. Joint work with Judit Abardia-Ev\'equoz and Andreas Bernig. Author affiliation: Vienna Institute of Technology Postdoctoral Unreviewed Non UBC

For detailed case information related to the slide, see the documents 'Key to respiratory pathology Aperio histology cases - Signalment, no diagnoses' accessible at http://hdl.handle.net/10214/16411 and 'Key to respiratory pathology Aperio histology cases - Diagnoses' accessible at http://hdl.handle.net/10214/16410. Respiratory pathology digital histology slide.

We discuss the defocusing energy-critical nonlinear wave equation in four dimensions. For deterministic and smooth initial data, solutions exist globally and scatter. In contrast, since deterministic and rough initial data can lead to norm inflation, the energy-critical NLW is ill-posed at low regularities. In this talk, we show that the global existence and scattering behavior persists under random and rough perturbations of the initial data. In particular, norm inflation only occurs for exceptional sets of rough initial data. As part of the argument, we discuss techniques from restriction theory, such as wave packet decompositions and Bourgain's bush argument. Author affiliation: University of California, Los Angeles Unreviewed Graduate Non UBC

It is widely known that persistent homology in more than one parameter is significantly more "complicated" than in the single-parameter setting. In this talk I will discuss in what sense it is more complicated from the point of view of representation theory, and from the point of view of algorithms. I will also give examples of how multi-parameter persistence modules naturally appear in applications. Author affiliation: Technical University Munich/VU Amsterdam Postdoctoral Unreviewed Non UBC

Seed dispersal is a key process driving the structure, composition, and regeneration of tropical forests. Larger frugivores play a crucial role in community structuring by dispersing large seeds not dispersed by smaller frugivores. We assessed the hypothesis that brown howler monkeys (Alouatta guariba clamitans) provide seed dispersal services for a wide assemblage of plant species in both small and large Atlantic forest fragments. Although fruit availability often decreases in small fragments compared with large ones, we predicted that brown howlers are efficient seed dispersers in quantitative and qualitative terms in both forest types given their high dietary flexibility. After a 36-month study period and 2,962 sampling hours, we found that howlers swallowed and defecated intact the vast majority of seeds (96%-100%) they handled in all study sites. Overall, they defecated ca. 315,600 seeds belonging to 98 species distributed in eight growth forms. We estimated that each individual howler dispersed an average of 143 (SD = 49) seeds >2 mm per day or 52,052 (SD = 17,782) seeds per year. They dispersed seeds of 58% to 93% of the local assemblages of fleshy-fruit trees. In most cases, the richness and abundance of seed species dispersed was similar between small and large fragments. However, groups inhabiting small fragments tended to disperse a higher diversity of seeds from rarely consumed fruits than those living in large fragments. We conclude that brown howlers are legitimate seed dispersers for most fleshy-fruit species of the angiosperm assemblages of their habitats, and that they might favor the regeneration of Atlantic forest fragments with the plentiful amount of intact seeds that they disperse each year. Dataset_seeds_dispersedHere we provided data on seed dispersal by six wild groups of brown howler monkeys (Alouatta guariba clamitans). This research was conducted during a 36-month period in three small (<10 ha: S1, S2, and S3) and three large (>90 ha: L1,L2, and L3) Atlantic forest fragments in Rio Grande do Sul State, southern Brazil.Dataset_seed_handlingHere we provided data on seed/fruit handling by six wild groups of brown howler monkeys (Alouatta guariba clamitans). This research was conducted during a 36-month period in three small (<10 ha: S1, S2, and S3) and three large (>90 ha: L1,L2, and L3) Atlantic forest fragments in Rio Grande do Sul State, southern Brazil.

In this talk I will survey some results on and techniques to study actions of (finite-dimensional) Hopf algebras on noncommutative algebras. Many examples will be provided and the categorical context for such results will be emphasized. Author affiliation: University of Illinois at Urbana–Champaign Unreviewed Faculty Non UBC

Newly replicated circular chromosomes are topologically linked. XerCD-dif- FtsK recombination acts in the replication termination region of the Escherichia coli chromosome to remove links introduced during homologous recombination and replication, whereas Topoisomerase IV removes replication links only. Based on gel mobility patterns of the products of recombination, a stepwise unlinking pathway has been proposed. We show definitively that there is a unique shortest pathway of unlinking by XerCD-dif-FtsK that strictly reduces the complexity of the links at every step. We delineate the mechanism of action of the enzymes at each step along this pathway and provide a 3D interpretation of the results. This is joint work with Koya Shimokawa, Kai Ishihara, Ian Grainge and David Sherratt. Author affiliation: Mathematics Department, San Francisco State University Unreviewed Faculty Non UBC

In tree canopies, incoming solar radiation interacts with leaves and branches to generate temperature differences within and among leaves, presenting thermal opportunities and risks for leaf-dwelling ectotherms. Although leaf biophysics and insect thermal ecology are well understood, few studies have examined them together in single systems. We examined temperature variability in aspen canopies, Populus tremuloides, and its consequences for a common herbivore, the leaf-mining caterpillar Phyllocnistis populiella. We shaded leaves in the field and measured effects on leaf temperature and larval growth and survival. We also estimated larval thermal performance curves for feeding and growth and measured upper lethal temperatures. Sunlit leaves directly facing the incoming rays reached the highest temperatures, typically 3 – 8 °C above ambient air temperature. Irradiance driven increases in temperatures, however, were transient enough that they did not alter observed growth rates of leaf miners. Incubator and ramping experiments suggested that larval performance peaks between 25 and 32 °C and declines to zero between 35 and 40 °C, depending on duration of temperature exposure. Upper lethal temperatures during one-hour heat shocks were 42 – 43 °C. When larvae were active in early spring, temperatures generally were low enough to depress rates of feeding and growth below their maxima, and only rarely did estimated mine temperatures rise beyond optimal temperatures. Observed leaf or mine temperatures never approached larval upper lethal temperatures. At this site during our experiments, larvae thus appeared to have a significant thermal safety margin; the more pressing problem was inadequate heat. Detailed information on mine temperatures and larval performance curves, however, allowed us to leverage long-term data sets on air temperature to estimate potential future shifts in performance and longer-term risks to larvae from lethally high temperatures. This analysis suggests that, in the past 20 years, larval performance has often been limited by cold and that the risk of heat stress has been low. Future warming will raise mean rates of feeding and growth but also the risk of exposure to injuriously or lethally high temperatures. These data were collected primarily at the MPG North Ranch, as detailed in the associated paper. The data are derived from weather stations, local measurements of leaf temperatures using thermocouples and infrared cameras, measurements of feeding, growth, and survival of larvae of the aspen leaf miner (Phyllocnistis populiella) as functions of temperature. Some growth data were obtained at the University of Montana. Scripts and data files are arranged by the figures in which they occur (Figures 3 - 12 in the main paper). Each R script reads in the necessary data from associated .csv or .txt files. One figure (Figure 3) also requires reading in a set of raw files from data loggers, which are provided in two zip files. The script provides a call to unzip those files locally.