2,443 research outputs found
Amelogenin: A Potential Regulator of CementumâAssociated Genes
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142042/1/jper1423.pd
Phylogenetics, morphological evolution, and classification of Euphorbia subgenus Euphorbia
Euphorbia subg. Euphorbia is the largest and most diverse of four recently recognized subgenera within Euphorbia and is distributed across the tropics and subtropics. Relationships within this group have been difficult to discern due mainly to homoplasious morphological characters and inadequate taxon sampling in previous phylogenetic studies. Here we present a phylogenetic analysis of E. subg. Euphorbia, using one nuclear and two plastid regions, for the most complete sampling of molecular sequence data to date. We assign 661 species to the subgenus and show that it is comprised of four highly supported clades, including a single New World clade and multiple independent lineages on Madagascar. Using this phylogenetic framework we discuss patterns of homoplasy in morphological evolution and general patterns of biogeography. Finally, we present a new sectional classification of E. subg. Euphorbia comprising 21 sections, nine of them newly described here.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147178/1/tax6225-sup-003-pdf.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147178/2/tax6225.pd
Evolutionary bursts in Euphorbia (Euphorbiaceae) are linked with photosynthetic pathway
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109954/1/evo12534.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/109954/2/evo12534-sup-0001-SuppMAT.pd
Ants Sow the Seeds of Global Diversification in Flowering Plants
Background: The extraordinary diversification of angiosperm plants in the Cretaceous and Tertiary periods has produced an
estimated 250,000â300,000 living angiosperm species and has fundamentally altered terrestrial ecosystems. Interactions
with animals as pollinators or seed dispersers have long been suspected as drivers of angiosperm diversification, yet
empirical examples remain sparse or inconclusive. Seed dispersal by ants (myrmecochory) may drive diversification as it can reduce extinction by providing selective advantages to plants and can increase speciation by enhancing geographical
isolation by extremely limited dispersal distances.
Methodology/Principal Findings: Using the most comprehensive sister-group comparison to date, we tested the hypothesis that myrmecochory leads to higher diversification rates in angiosperm plants. As predicted, diversification rates
were substantially higher in ant-dispersed plants than in their non-myrmecochorous relatives. Data from 101 angiosperm
lineages in 241 genera from all continents except Antarctica revealed that ant-dispersed lineages contained on average
more than twice as many species as did their non-myrmecochorous sister groups. Contrasts in species diversity between
sister groups demonstrated that diversification rates did not depend on seed dispersal mode in the sister group and were
higher in myrmecochorous lineages in most biogeographic regions.
Conclusions/Significance: Myrmecochory, which has evolved independently at least 100 times in angiosperms and is
estimated to be present in at least 77 families and 11 000 species, is a key evolutionary innovation and a globally important driver of plant diversity. Myrmecochory provides the best example to date for a consistent effect of any mutualism on largescale diversification
Effect of race on prediction of brain amyloidosis by plasma Aβ42/Aβ40, phosphorylated tau, and neurofilament light
BACKGROUND AND OBJECTIVES: To evaluate whether plasma biomarkers of amyloid (Aβ42/Aβ40), tau (p-tau181 and p-tau231), and neuroaxonal injury (neurofilament light chain [NfL]) detect brain amyloidosis consistently across racial groups.
METHODS: Individuals enrolled in studies of memory and aging who self-identified as African American (AA) were matched 1:1 to self-identified non-Hispanic White (NHW) individuals by age,
RESULTS: There were 76 matched pairs of AA and NHW participants (n = 152 total). For both AA and NHW groups, the median age was 68.4 years, 42% were
DISCUSSION: Models predicting brain amyloidosis using a high-performance plasma Aβ42/Aβ40 assay may provide an accurate and consistent measure of brain amyloidosis across AA and NHW groups, but models based on plasma p-tau181, p-tau231, and NfL may perform inconsistently and could result in disproportionate misdiagnosis of AA individuals
NASA Langley Experimental Aerothermodynamic Contributions to Slender and Winged Hypersonic Vehicles
No abstract availabl
Bisphosphonate Modulates Cementoblast Behavior In Vitro
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142297/1/jper1890.pd
Characterization of Shewanella oneidensis MtrC: a cell-surface decaheme cytochrome involved in respiratory electron transport to extracellular electron acceptors
MtrC is a decaheme c-type cytochrome associated with the outer cell membrane of Fe(III)-respiring species of the Shewanella genus. It is proposed to play a role in anaerobic respiration by mediating electron transfer to extracellular mineral oxides that can serve as terminal electron acceptors. The present work presents the first spectropotentiometric and voltammetric characterization of MtrC, using protein purified from Shewanella oneidensis MR-1. Potentiometric titrations, monitored by UVâvis absorption and electron paramagnetic resonance (EPR) spectroscopy, reveal that the hemes within MtrC titrate over a broad potential range spanning between approximately +100 and approximately -500 mV (vs. the standard hydrogen electrode). Across this potential window the UVâvis absorption spectra are characteristic of low-spin c-type hemes and the EPR spectra reveal broad, complex features that suggest the presence of magnetically spin-coupled low-spin c-hemes. Non-catalytic protein film voltammetry of MtrC demonstrates reversible electrochemistry over a potential window similar to that disclosed spectroscopically. The voltammetry also allows definition of kinetic properties of MtrC in direct electron exchange with a solid electrode surface and during reduction of a model Fe(III) substrate. Taken together, the data provide quantitative information on the potential domain in which MtrC can operate
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