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Mitchell, United States

The Mitchell Institute is a 501 non-profit organization in Portland, Maine which has as its mission to increase the likelihood that young people from Maine will aspire to, pursue and achieve a college education.The Institute was founded by George J. Mitchell and is supported by donors throughout Maine. The Institute features a quotation from George J. Mitchell that "no one should be guaranteed success ... but everyone should have a fair chance to succeed." Wikipedia.


Jansson J.K.,Lawrence Berkeley National Laboratory | Jansson J.K.,Mitchell Institute | Jansson J.K.,Joint BioEnergy Institute | Jansson J.K.,Copenhagen University | And 2 more authors.
Nature Reviews Microbiology | Year: 2014

Permafrost constitutes a major portion of the terrestrial cryosphere of the Earth and is a unique ecological niche for cold-adapted microorganisms. There is a relatively high microbial diversity in permafrost, although there is some variation in community composition across different permafrost features and between sites. Some microorganisms are even active at subzero temperatures in permafrost. An emerging concern is the impact of climate change and the possibility of subsequent permafrost thaw promoting microbial activity in permafrost, resulting in increased potential for greenhouse-gas emissions. This Review describes new data on the microbial ecology of permafrost and provides a platform for understanding microbial life strategies in frozen soil as well as the impact of climate change on permafrost microorganisms and their functional roles. © 2014 Macmillan Publishers Limited. All rights reserved.


We have developed a new approach to systematically study post-transcriptional regulation in a small number of cells. Actively translating mRNAs are associated with polysomes and the newly synthesized peptide chains are closely associated with molecular chaperones such as hsp70s, which assist in the proper folding of nascent polypeptides into higher ordered structures. These chaperones provide an anchor with which to separate actively translating mRNAs associated with polysomes from free mRNAs. Affinity capture beads were developed to capture hsp70 chaperones associated with the polysome complexes. The isolated actively translating mRNAs were used for high-throughput expression profiling analysis. Feasibility was demonstrated using an in vitro translation system with known translationally regulated mRNA transcript thymidylate synthase (TS). We further developed the approach using HCT-116 colon cancer cells with both TS and p53 as positive controls. The steady-state levels of TS and p53 mRNAs were unaltered after 5-fluorouracil treatment as assessed by real-time qRT-PCR analysis. In contrast, the protein expression and polysome-associated mRNA levels of both genes were increased. These differences in translational rate were revealed with our new approach from 500 cells. This technology has the potential to make investigation of translational control feasible with limited quantities of clinical specimens.


Lowe C.J.,Stanford University | Clarke D.N.,Stanford University | Medeiros D.M.,University of Colorado at Boulder | Rokhsar D.S.,University of California at Berkeley | And 3 more authors.
Nature | Year: 2015

Our understanding of vertebrate origins is powerfully informed by comparative morphology, embryology and genomics of chordates, hemichordates and echinoderms, which together make up the deuterostome clade. Striking body-plan differences among these phyla have historically hindered the identification of ancestral morphological features, but recent progress in molecular genetics and embryology has revealed deep similarities in body-axis formation and organization across deuterostomes, at stages before morphological differences develop. These developmental genetic features, along with robust support of pharyngeal gill slits as a shared deuterostome character, provide the foundation for the emergence of chordates. © 2015 Macmillan Publishers Limited. All rights reserved.


Silke J.,Walter and Eliza Hall Institute of Medical Research | Meier P.,Mitchell Institute
Cold Spring Harbor Perspectives in Biology | Year: 2013

Misregulated innate immune signaling and cell death form the basis of much human disease pathogenesis. Inhibitor of apoptosis (IAP) protein family members are frequently overex- pressed in cancer and contribute to tumor cell survival, chemo-resistance, disease progres- sion, and poor prognosis. Although best known for theirabilitytoregulate caspases, IAPs also influence ubiquitin (Ub)-dependent pathways that modulate innate immune signaling via activation of nuclear factor kB (NF-kB). Recent research into IAP biology has unearthed unexpected roles for this group of proteins. In addition, the advances in our understanding of the molecular mechanisms that IAPs use to regulate cell death and innate immune re- sponses have provided new insights into disease states and suggested novel intervention strategies. Here we review the functions assigned to those IAP proteins that act at the inter- section of cell death regulation and inflammatory signaling. © 2013 Cold Spring Harbor Laboratory Press; all rights reserved.


Sullivan T.P.,University of British Columbia | Sullivan D.S.,Mitchell Institute
Forest Ecology and Management | Year: 2010

Voles of the genera Microtus and Myodes feed on tree seedlings planted on cutover forest land in temperate and boreal forests of North America and Eurasia. This damage may have serious economic implications as well as limit regeneration of appropriate tree species in certain forest ecosystems. Prediction of vole population outbreaks and feeding damage to forest plantations, across even a limited geographic range, has yet to be achieved in North America. Thus, a major objective was a detailed analysis of changes in population dynamics of long-tailed voles (Microtus longicaudus), and to test three hypotheses (H) that vole populations would: (H1) rise and fall in accordance with the abundance of herbaceous plants (grasses and forbs) during early vegetative succession after forest harvesting, (H2) be positively associated with grass-seeded sites; and (H3) incidence of feeding damage to seedlings would be positively associated with vole abundance. Voles were live-trapped for 6 years (2004-2009) from the time of harvesting on intensive sites, as well as surveyed over a range of extensive sites. Population numbers were related to habitat characteristics and tree damage in young forest plantations near Golden, British Columbia, Canada.Populations of long-tailed voles were low in the first two years after harvest with mean numbers <5-15/ha. Annual peaks of 49-84 voles/ha were recorded in 2006. In the fourth year (2007) after harvesting, numbers of voles declined on two of three sites, deepened in 2008 and reached extirpation in 2009. On the extensive sites, vole numbers increased 4.6-5.3 times from 1-2 to 3-6 years post-harvest before declining thereafter. Crown volume index of grasses and herbs, volume and abundance of downed wood, total species richness of vascular plants, and structural diversity of herbs were important habitat variables. Vole numbers were higher on those sites seeded with pasture grasses and forbs. There was a significant positive relationship of tree mortality and abundance of voles (Microtus) across a relatively wide geographic area.This study is the first relatively long-term analysis of changes in population dynamics of the long-tailed vole and the predictions of H1 and H2 seemed to be supported. The positive relationship (H3) of the incidence of overwinter damage to trees and vole abundance is the first such analysis for forest plantations, on harvested sites, in North America. At 3-4 years post-clearcut harvesting is a critical time for population buildups of voles and subsequent damage to plantation trees. Seeded grass species clearly create optimum habitat conditions for voles, generating population densities up to 30-50 voles/ha, which is in the range of a " high" damage risk to seedlings. Risk ratings (voles/ha) for feeding damage to trees were low (<7), moderate (7-34), high (35-88), and very high (>88). © 2010 Elsevier B.V.

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