Effects of Chemical Variation on Competition and Insect Communities Across Solidago altissima Genotypes

Individuals within a plant species can differ greatly from one another, especially regarding the range of chemical compounds produced. However, the functions of many of these chemicals are unknown, but likely include defenses against herbivores, attractants for pollinators and seed dispersers, as well as mechanisms for resource competition. To assess the effects of foliar chemical composition on interspecific plant competition and insect communities, I conducted a common garden and greenhouse experiment using 24 genotypes of the allelopathic species Solidago altissima for which the foliar chemistry had been characterized. Using these data and chemical profiles of S. altissima, I linked foliar chemistry to plant performance, competitive ability and the foliar/floral insect communities. The common garden experiment showed there was great variation in foliar chemistry between the genotypes. Ecological patterns existed between foliar chemistry and plant performance, as foliar chemistry was strongly related to most measures of plant performance across genotypes. Pollinator communities were found to relate with total aboveground biomass, proportion of flower mass, and % light transmittance as well as plant chemistry. The greenhouse experiment showed marked variation in both rhizome and above-ground biomass growth for S. altissima. The above-ground biomass of Abutilon theophrasti, S. scoparium, and S. integrifolium had their biomass significantly reduced via competition with S. altissima. Chemistry significantly affected the biomass of both A. theophrasti and S. scoparium, suggesting that chemistry is a critical driver of competition for S. altissima

On Capturing the Ineffable: A Moment from Experimental Film 59.10

This artwork is a still from “59,” an experimental film installation I created with the following restrictions: I had to direct eleven 59-second films in eleven months with eleven collaborating artists, none of whom could be cis men.In the resulting project, we used film and those eleven short moments to capture our unique, fragile experiences. We explored everything from the way in which facets of personality drift in and out of the subconscious to the beautiful, mercurial nature of gender

Infectious etiologies of acute otitis media

There is no preferred method for establishing the infectious etiology of acute otitis media (AOM). Bacterial or viral pathogens are found in most cases. Bacterial pathogens are more common than viruses in middle ear fluid samples collected from children with AOM and intact tympanic membranes. Studies using newer detection methods reveal more viral pathogens than those using less sensitive methods

A House with Two Rooms: Final Report of the Truth and Reconciliation Commission of Liberia Diaspora Project

From 1979 to 2003, more than 1.5 million Liberians were forced from their homes to escape from the violence and destruction of a protracted civil conflict. Hundreds of thousands became refugees and many eventually made their way to countries of resettlement including the United States and the United Kingdom. Most of their stories have never been told. This report on the experience of the Liberian diaspora, entitled A House with Two Rooms, is the culmination of three years of work in the United States, the United Kingdom and Buduburam Refugee Settlement in Ghana. The report has been submitted to the Liberian Truth and Reconciliation Commission (TRC), the body charged by the Liberian government with determining the facts of the human rights violations that occurred during the civil war. The Liberian TRC officially completed its mandate June 30, 2009.https://open.mitchellhamline.edu/dri_press/1006/thumbnail.jp

The 2010 Maule, Chile earthquake: Downdip rupture limit revealed by space geodesy

Radar interferometry from the ALOS satellite captured the coseismic ground deformation associated with the 2010 Mw 8.8 Maule, Chile earthquake. The ALOS interferograms reveal a sharp transition in fringe pattern at ~150 km from the trench axis that is diagnostic of the downdip rupture limit of the Maule earthquake. An elastic dislocation model based on ascending and descending ALOS interferograms and 13 near-field 3-component GPS measurements reveals that the coseismic slip decreases more or less linearly from a maximum of 17 m (along-strike average of 6.5 m) at 18 km depth to near zero at 43–48 km depth, quantitatively indicating the downdip limit of the seismogenic zone. The depth at which slip drops to near zero appears to be at the intersection of the subducting plate with the continental Moho. Our model also suggests that the depth where coseismic slip vanishes is nearly uniform along the strike direction for a rupture length of ~600 km. The average coseismic slip vector and the interseismic velocity vector are not parallel, which can be interpreted as a deficit in strike-slip moment release

Fragmentation and mass segregation in the massive dense cores of Cygnus X

We present Plateau de Bure interferometer observations obtained in continuum at 1.3 and 3.5 mm towards the six most massive and young (IR-quiet) dense cores in Cygnus X. Located at only 1.7 kpc, the Cygnus X region offers the opportunity of reaching small enough scales (of the order of 1700 AU at 1.3 mm) to separate individual collapsing objects. The cores are sub-fragmented with a total of 23 fragments inside 5 cores. Only the most compact core, CygX-N63, could actually be a single massive protostar with an envelope mass as large as 60 Msun. The fragments in the other cores have sizes and separations similar to low-mass pre-stellar and proto-stellar condensations in nearby protoclusters, and are probably of the same nature. A total of 9 out of these 23 protostellar objects are found to be probable precursors of OB stars with envelope masses ranging from 6 to 23 Msun. The level of fragmentation is globally higher than in the turbulence regulated, monolithic collapse scenario, but is not as high as expected in a pure gravo-turbulent scenario where the distribution of mass is dominated by low-mass protostars/stars. Here, the fractions of the total core masses in the high-mass fragments are reaching values as high as 28, 44, and 100 % in CygX-N12, CygX-N53, and CygX-N63, respectively, much higher than what an IMF-like mass distribution would predict. The increase of the fragmentation efficiency as a function of density in the cores is proposed to be due to the increasing importance of self-gravity leading to gravitational collapse at the scale of the dense cores. At the same time, the cores tend to fragment into a few massive protostars within their central regions. We are therefore probably witnessing here the primordial mass segregation of clusters in formation.Comment: 14 pages, 16 figures, submitted for publication in A&