Phytochemical changes in milkweed induced by elevated CO2 alter wing morphology but not toxin sequestration in monarch butterflies

Environmental change has the potential to influence trophic interactions by altering the defensive phenotype of prey.Here, we examine the effects of a pervasive environmental change driver, elevated atmospheric concentrations of CO2 (eCO2), on toxin sequestration and flight morphology of a specialist herbivore.We fed monarch butterfly larvae, Danaus plexippus, foliage from four milkweed, Asclepias, species of varying chemical defence profiles grown under either ambient or eCO2. We also infected a subset of these herbivores with a protozoan parasite, Ophryocystis elektroscirrha, to understand how infection and environmental change combine to alter herbivore defences. We measured changes in phytochemistry induced by eCO2 and assessed cardenolide, toxic steroid, sequestration and wing morphology of butterflies.Monarchs compensated for lower plant cardenolide concentrations under eCO2 by increasing cardenolide sequestration rate, maintaining similar cardenolide composition and concentrations in their wings under both CO2 treatments. We suggest that these increases in sequestration rate are a by‐product of compensatory feeding aimed at maintaining a nutritional target in response to declining dietary quality under eCO2.Monarch wings were more suitable for sustained flight (more elongated) when reared on plants grown under eCO2 or when reared on Asclepias syriaca or Asclepias incarnata rather than on Asclepias curassavica or Asclepias speciosa. Parasite infection engendered wings less suitable for sustained flight (wings became rounder) on three of four milkweed species. Wing loading (associated with powered flight) was higher on A. syriaca than on other milkweeds, whereas wing density was lower on A. curassavica. Monarchs that fed on high cardenolide milkweed developed rounder, thinner wings, which are less efficient at gliding flight.Ingesting foliage from milkweed high in cardenolides may provide protection from enemies through sequestration yet come at a cost to monarchs manifested as lower quality flight phenotypes: rounder, thinner wings with lower wing loading values.Small changes in morphology may have important consequences for enemy evasion and migration success in many animals. Energetic costs associated with alterations in defence and morphology may, therefore, have important consequences for trophic interactions in a changing world.A plain language summary is available for this article.Plain Language SummaryPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/1/fec13270-sup-0006-TableS2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/2/fec13270-sup-0003-FigS2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/3/fec13270-sup-0004-FigS3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/4/fec13270-sup-0002-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/5/fec13270-sup-0008-TableS4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/6/fec13270-sup-0005-TableS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/7/fec13270-sup-0009-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/8/fec13270_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/9/fec13270-sup-0001-Summary.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/10/fec13270.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148239/11/fec13270-sup-0007-TableS3.pd

Oxygen poisoning in micro-organisms and its relation to the toxicity of oxygen at high pressure on mammalian tissue

No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50113/1/1030170303_ftp.pd

A Hybrid Heuristic for the k-medoids Clustering Problem

Clustering is an important tool for data analysis, since it allows the exploration of datasets with no or very little prior information. Its main goal is to group a set of data based on their similarity (dissimilarity). A well known mathematical formulation for clustering is the k-medoids problem. Current versions of k-medoids rely on heuristics, with good results reported in the literature. However, few methods that analyze the quality of the partitions found by the heuristics have been proposed. in this paper, we propose a hybrid Lagrangian heuristic for the k-medoids. We compare the performance of the proposed Lagrangian heuristic with other heuristics for the k-medoids problem found in literature. Experimental results presented that the proposed Lagrangian heuristic outperformed the other algorithms.UNIFESP, Inst Ciencia & Tecnol, BR-12230280 Sao Jose Dos Campos, SP, BrazilUNIFESP, Inst Ciencia & Tecnol, BR-12230280 Sao Jose Dos Campos, SP, BrazilWeb of Scienc

Microbial Communities Under Distinct Thermal and Geochemical Regimes in Axial and Off-Axis Sediments of Guaymas Basin

Cold seeps and hydrothermal vents are seafloor habitats fueled by subsurface energy sources. Both habitat types coexist in Guaymas Basin in the Gulf of California, providing an opportunity to compare microbial communities with distinct physiologies adapted to different thermal regimes. Hydrothermally active sites in the southern Guaymas Basin axial valley, and cold seep sites at Octopus Mound, a carbonate mound with abundant methanotrophic cold seep fauna at the Central Seep location on the northern off-axis flanking regions, show consistent geochemical and microbial differences between hot, temperate, cold seep, and background sites. The changing microbial actors include autotrophic and heterotrophic bacterial and archaeal lineages that catalyze sulfur, nitrogen, and methane cycling, organic matter degradation, and hydrocarbon oxidation. Thermal, biogeochemical, and microbiological characteristics of the sampling locations indicate that sediment thermal regime and seep-derived or hydrothermal energy sources structure the microbial communities at the sediment surface

First direct observation of Dirac fermions in graphite

Originating from relativistic quantum field theory, Dirac fermions have been recently applied to study various peculiar phenomena in condensed matter physics, including the novel quantum Hall effect in graphene, magnetic field driven metal-insulator-like transition in graphite, superfluid in 3He, and the exotic pseudogap phase of high temperature superconductors. Although Dirac fermions are proposed to play a key role in these systems, so far direct experimental evidence of Dirac fermions has been limited. Here we report the first direct observation of massless Dirac fermions with linear dispersion near the Brillouin zone (BZ) corner H in graphite, coexisting with quasiparticles with parabolic dispersion near another BZ corner K. In addition, we report a large electron pocket which we attribute to defect-induced localized states. Thus, graphite presents a novel system where massless Dirac fermions, quasiparticles with finite effective mass, and defect states all contribute to the low energy electronic dynamics.Comment: Nature Physics, in pres

Tumor cell heterogeneity and resistance; report from the 2018 Coffey‐Holden Prostate Cancer Academy Meeting

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147081/1/pros23729.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147081/2/pros23729_am.pd

Hypokalemic Periodic Paralysis: a case report and review of the literature

Hypokalemic Periodic Paralysis is one form of Periodic Paralysis, a rare group of disorders that can cause of sudden onset weakness. A case of a 29 year old male is presented here. The patient presented with sudden onset paralysis of his extremities. Laboratory evaluation revealed a markedly low potassium level. The patient's paralysis resolved upon repletion of his low potassium and he was discharged with no neurologic deficits. An association with thyroid disease is well established and further workup revealed Grave's disease in this patient. Although rare, Periodic Paralysis must differentiated from other causes of weakness and paralysis so that the proper treatment can be initiated quickly

Microbial communities under distinct thermal and geochemical regimes in axial and off-axis sediments of Guaymas Basin

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Teske, A., Wegener, G., Chanton, J. P., White, D., MacGregor, B., Hoer, D., de Beer, D., Zhuang, G., Saxton, M. A., Joye, S. B., Lizarralde, D., Soule, S. A., & Ruff, S. E. Microbial communities under distinct thermal and geochemical regimes in axial and off-axis sediments of Guaymas Basin. Frontiers in Microbiology, 12, (2021): 633649, https://doi.org/10.3389/fmicb.2021.633649.Cold seeps and hydrothermal vents are seafloor habitats fueled by subsurface energy sources. Both habitat types coexist in Guaymas Basin in the Gulf of California, providing an opportunity to compare microbial communities with distinct physiologies adapted to different thermal regimes. Hydrothermally active sites in the southern Guaymas Basin axial valley, and cold seep sites at Octopus Mound, a carbonate mound with abundant methanotrophic cold seep fauna at the Central Seep location on the northern off-axis flanking regions, show consistent geochemical and microbial differences between hot, temperate, cold seep, and background sites. The changing microbial actors include autotrophic and heterotrophic bacterial and archaeal lineages that catalyze sulfur, nitrogen, and methane cycling, organic matter degradation, and hydrocarbon oxidation. Thermal, biogeochemical, and microbiological characteristics of the sampling locations indicate that sediment thermal regime and seep-derived or hydrothermal energy sources structure the microbial communities at the sediment surface.Research on Guaymas Basin in the Teske lab is supported by NSF Molecular and cellular Biology grant 1817381 “Collaborative Research: Next generation physiology: a systems-level understanding of microbes driving carbon cycling in marine sediments”. Sampling in Guaymas Basin was supported by collaborative NSF Biological Oceanography grants 1357238 and 1357360 “Collaborative Research: Microbial carbon cycling and its interaction with sulfur and nitrogen transformations in Guaymas Basin hydrothermal sediments” to AT and SJ, respectively. SER was supported by an AITF/Eyes High Postdoctoral Fellowship and start-up funds provided by the Marine Biological Laboratory

The impact of low input DNA on the reliability of DNA methylation as measured by the Illumina Infinium MethylationEPIC BeadChip

DNA methylation (DNAm) is commonly assayed using the Illumina Infinium MethylationEPIC BeadChip, but there is currently little published evidence to define the lower limits of the amount of DNA that can be used whilst preserving data quality. Such evidence is valuable for analyses utilizing precious or limited DNA sources. We used a single pooled sample of DNA in quadruplicate at three dilutions to define replicability and noise, and an independent population dataset of 328 individuals (from a community-based study including US-born non-Hispanic Black and white persons) to assess the impact of total DNA input on the quality of data generated using the Illumina Infinium MethylationEPIC BeadChip. We found that data are less reliable and more noisy as DNA input decreases to 40ng, with clear reductions in data quality; and that low DNA input is associated with a reduction in power to detect EWAS associations, requiring larger sample sizes. We conclude that DNA input as low as 40ng can be used with the Illumina Infinium MethylationEPIC BeadChip, provided quality checks and sensitivity analyses are undertaken

Effect of magnetic nanoparticles on the nematic-smectic-A phase transition

Recent experiments on mixed liquid crystals have highlighted the hugely significant role of ferromagnetic nanoparticle impurities in defining the nematic-smectic-A phase transition point. Structured around a Flory-Huggins free energy of isotropic mixing and Landau-de Gennes free energy, this article presents a phenomenological mean-field model that quantifies the role of such impurities in analyzing thermodynamic phases, in a mixture of thermotropic smectic liquid crystal and ferromagnetic nanoparticles. First we discuss the impact of ferromagnetic nanoparticles on the isotropic-ferronematic and ferronematic-ferrosmectic phase transitions and their transition temperatures. This is followed by plotting and discussing various topologies in the phase diagrams. Our model results indicate that there exists a critical concentration of nanoparticle impurities for which the second order N-SmA transition becomes first order at a tricritical point. Calculations based on this model show remarkable agreement with experiment