88 research outputs found

    Sustaining Progress towards NTD Elimination: An Opportunity to Leverage Lymphatic Filariasis Elimination Programs to Interrupt Transmission of Soil-Transmitted Helminths

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    Copyright © 2016 Means et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

    Pleistocene Climate, Phylogeny, and Climate Envelope Models: An Integrative Approach to Better Understand Species' Response to Climate Change

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    Mean annual temperature reported by the Intergovernmental Panel on Climate Change increases at least 1.1°C to 6.4°C over the next 90 years. In context, a change in climate of 6°C is approximately the difference between the mean annual temperature of the Last Glacial Maximum (LGM) and our current warm interglacial. Species have been responding to changing climate throughout Earth's history and their previous biological responses can inform our expectations for future climate change. Here we synthesize geological evidence in the form of stable oxygen isotopes, general circulation paleoclimate models, species' evolutionary relatedness, and species' geographic distributions. We use the stable oxygen isotope record to develop a series of temporally high-resolution paleoclimate reconstructions spanning the Middle Pleistocene to Recent, which we use to map ancestral climatic envelope reconstructions for North American rattlesnakes. A simple linear interpolation between current climate and a general circulation paleoclimate model of the LGM using stable oxygen isotope ratios provides good estimates of paleoclimate at other time periods. We use geologically informed rates of change derived from these reconstructions to predict magnitudes and rates of change in species' suitable habitat over the next century. Our approach to modeling the past suitable habitat of species is general and can be adopted by others. We use multiple lines of evidence of past climate (isotopes and climate models), phylogenetic topology (to correct the models for long-term changes in the suitable habitat of a species), and the fossil record, however sparse, to cross check the models. Our models indicate the annual rate of displacement in a clade of rattlesnakes over the next century will be 2 to 3 orders of magnitude greater (430-2,420 m/yr) than it has been on average for the past 320 ky (2.3 m/yr)

    Stem cell function and stress response are controlled by protein synthesis.

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    Whether protein synthesis and cellular stress response pathways interact to control stem cell function is currently unknown. Here we show that mouse skin stem cells synthesize less protein than their immediate progenitors in vivo, even when forced to proliferate. Our analyses reveal that activation of stress response pathways drives both a global reduction of protein synthesis and altered translational programmes that together promote stem cell functions and tumorigenesis. Mechanistically, we show that inhibition of post-transcriptional cytosine-5 methylation locks tumour-initiating cells in this distinct translational inhibition programme. Paradoxically, this inhibition renders stem cells hypersensitive to cytotoxic stress, as tumour regeneration after treatment with 5-fluorouracil is blocked. Thus, stem cells must revoke translation inhibition pathways to regenerate a tissue or tumour.This work was funded by Cancer Research UK (CR-UK), Worldwide Cancer Research, the Medical Research Council (MRC), the European Research Council (ERC), and EMBO. Research in Michaela Frye's laboratory is supported by a core support grant from the Wellcome Trust and MRC to the Wellcome Trust-Medical Research Cambridge Stem Cell Institute.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nature1828

    Argumentative writing behavior of graduate EFL learners

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.This study analyzed the argumentative writing behavior of Iranian graduate learners of English as Foreign Language in their English essays. Further, the correlations between the use of argument elements and overall writing quality as well as soundness of produced arguments were investigated. To this end, 150 essays were analyzed. The sample essays were found to be predominantly deductive in terms of rhetorical pattern. Moreover, they mainly utilized ‘data’ and ‘claim’ most frequently with secondary elements of argument (i.e., counterargument claim, counterargument data, rebuttal claim, and rebuttal data) as the least produced elements. Overall writing quality co-varied significantly positively with the uses of claims, data, counterargument claims, counterargument data, rebuttal claims, and rebuttal data. Essays rated high in terms of overall writing quality were further rated for soundness and relevance of the arguments. The results demonstrate that even for advanced language learners good surface structure cannot necessarily guarantee well thought-out logical structure. The pedagogical implications for writing instruction and research are discussed

    Akt mediated mitochondrial protection in the heart: metabolic and survival pathways to the rescue

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    Exceptional diversity of Pristimantis Landfrogs (Anura: Terraranae) on the Wokomung Massif, Guyana, with descriptions of three new species

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    We describe three new species of landfrogs, genus Pristimantis, from near the summit of Mt. Kopinang, one of the several high points of the Wokomung Massif, a large horseshoe-shaped tepui (= mesa) in west-central Guyana. Pristimantis koki n. sp. is known from 1,067 to 1,525 m elevation. It is characterized by small-sized adults averaging 12.4 mm SVL (snout-vent length) in males and 18.4 mm in females; a pointed, depressed, elongated snout; lack of an obvious tympanum, vocal slit, or sac; and diagnostically black pigment prominently arranged around the anus fringed by light pigment. When handled, P. koki seems to emit volatile organic compounds and leaves a slightly numbing taste at the base of the human tongue. Pristimantis kopinangae n. sp. is known from three specimens collected at approx. 1,385 m elevation on the Wokomung Massif and two specimens from slightly higher in elevation on Mt. Ayanganna. About the size of most Pristimantis inhabiting the Guyana uplands and highlands (20-30 mm SVL), it is characterized by 2-3 light yellow inguinal flash-mark blotches, short broadly round snout, large eye with a blue iris, white skin of chin and areolate belly with dark brown vermiculations; and absence of a tympanum. Pristimantis kalamandeenae n. sp. is known from three specimens collected on the Wokomung Massif including an amplexing pair at approx. 1,550 m elevation. Similar in size to P. kopinangae, it is characterized by an acuminate snout, black iris, obvious tympanum, and uniform tan pigmentation dorsally after dark that becomes uniformly dark brown in daytime. Phylogenetic results show that P. koki and P. kopinangae are sister species and are members of a larger assemblage of related species endemic to the Pantepui Region within the P. unistrigatus species group. Pristimantis kalamandeenae is not closely related to these species, instead forming a clade with the P. lacrimosus species group. The three new species occur in sympatry with at least five other Pristimantis species on the Wokomung Massif, the greatest known Pristimantis species richness on a single tepui of the Guiana Shield.http://deepblue.lib.umich.edu/bitstream/2027.42/179210/2/49_Means et al. 2023 Pristimantis.pdfPublished versionDescription of 49_Means et al. 2023 Pristimantis.pdf : Published versio
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