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The world's biggest amphibians
\"Carefully leveled text and engaging full-color photos introduce early fluent readers to the world's biggest amphibians, describing their physical features and behavior while comparing aspects of their size to everyday items familiar to young readers. Includes activity, glossary, and index.\"-- Provided by publisher.
Book
Correction: A review of the elusive bicolored iris Snouted Treefrogs (Anura: Hylidae:Scinax uruguayus group)
[This corrects the article DOI: 10.1371/journal.pone.0222131.].
Journal Article
Name that amphibian!
Amphibians share many characteristics, including slimy-looking skin and a life cycle that includes time in the water and time on land. Many species of these fascinating animals have their own unique look. In this book, readers are introduced to the amphibian group.
Book
Efficient Expression of Functional .sub.2beta3 AChRs in Xenopus Oocytes from Free Subunits Using Slightly Modified alpha6 Subunits
Human ([alpha]6[beta]2)([alpha]4[beta]2)[beta]3 nicotinic acetylcholine receptors (AChRs) are essential for addiction to nicotine and a target for drug development for smoking cessation. Expressing this complex AChR is difficult, but has been achieved using subunit concatamers. In order to determine what limits expression of [alpha]6* AChRs and to efficiently express [alpha]6* AChRs using free subunits, we investigated expression of the simpler ([alpha]6[beta]2).sub.2 [beta]3 AChR. The concatameric form of this AChR assembles well, but is transported to the cell surface inefficiently. Various chimeras of [alpha]6 with the closely related [alpha]3 subunit increased expression efficiency with free subunits and produced pharmacologically equivalent functional AChRs. A chimera in which the large cytoplasmic domain of [alpha]6 was replaced with that of [alpha]3 increased assembly with [beta]2 subunits and transport of AChRs to the oocyte surface. Another chimera replacing the unique methionine 211 of [alpha]6 with leucine found at this position in transmembrane domain 1 of [alpha]3 and other [alpha] subunits increased assembly of mature subunits containing [beta]3 subunits within oocytes. Combining both [alpha]3 sequences in an [alpha]6 chimera increased expression of functional ([alpha]6[beta]2).sub.2 [beta]3 AChRs to 12-fold more than with concatamers. This is pragmatically useful, and provides insights on features of [alpha]6 subunit structure that limit its expression in transfected cells.
Journal Article
Creepy amphibians
Readers will learn all about the weird things amphibians do, including how some mother frogs birth their babies from under the skin on their back and that a salamander can re-grow its tail.
Book
Efficient Expression of Functional
Human ([alpha]6[beta]2)([alpha]4[beta]2)[beta]3 nicotinic acetylcholine receptors (AChRs) are essential for addiction to nicotine and a target for drug development for smoking cessation. Expressing this complex AChR is difficult, but has been achieved using subunit concatamers. In order to determine what limits expression of [alpha]6* AChRs and to efficiently express [alpha]6* AChRs using free subunits, we investigated expression of the simpler ([alpha]6[beta]2).sub.2 [beta]3 AChR. The concatameric form of this AChR assembles well, but is transported to the cell surface inefficiently. Various chimeras of [alpha]6 with the closely related [alpha]3 subunit increased expression efficiency with free subunits and produced pharmacologically equivalent functional AChRs. A chimera in which the large cytoplasmic domain of [alpha]6 was replaced with that of [alpha]3 increased assembly with [beta]2 subunits and transport of AChRs to the oocyte surface. Another chimera replacing the unique methionine 211 of [alpha]6 with leucine found at this position in transmembrane domain 1 of [alpha]3 and other [alpha] subunits increased assembly of mature subunits containing [beta]3 subunits within oocytes. Combining both [alpha]3 sequences in an [alpha]6 chimera increased expression of functional ([alpha]6[beta]2).sub.2 [beta]3 AChRs to 12-fold more than with concatamers. This is pragmatically useful, and provides insights on features of [alpha]6 subunit structure that limit its expression in transfected cells.
Journal Article
Salamander, frog, and polliwog : what is an amphibian?
What makes an amphibian an amphibian? All amphibians are cold-blooded and have backbones, but most amphibians share other characteristics as well. Rhymes from Brian P. Cleary and humorous illustrations from Martin Goneau provide a fun introduction to this animal group.
Book
Ongoing declines for the world’s amphibians in the face of emerging threats
Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.
Journal Article
Focus on amphibians
Presents amphibians and describes the bodies, life cycles, and habitats of various types.
Book
Biogeographic Analysis Reveals Ancient Continental Vicariance and Recent Oceanic Dispersal in Amphibians
Amphibia comprises over 7000 extant species distributed in almost every ecosystem on every continent except Antarctica. Most species also show high specificity for particular habitats, biomes, or climatic niches, seemingly rendering long-distance dispersal unlikely. Indeed, many lineages still seem to show the signature of their Pangaean origin, approximately 300 Ma later. To date, no study has attempted a large-scale historical-biogeographic analysis of the group to understand the distribution of extant lineages. Here, I use an updated chronogram containing 3309 species (~45% of extant diversity) to reconstruct their movement between 12 global ecoregions. I find that Pangaean origin and subsequent Laurasian and Gondwanan fragmentation explain a large proportion of patterns in the distribution of extant species. However, dispersal during the Cenozoic, likely across land bridges or short distances across oceans, has also exerted a strong influence. Finally, there are at least three strongly supported instances of long-distance oceanic dispersal between former Gondwanan landmasses during the Cenozoic. Extinction from intervening areas seems to be a strong factor in shaping present-day distributions. Dispersal and extinction from and between ecoregions are apparently tied to the evolution of extraordinarily adaptive expansion-oriented phenotypes that allow lineages to easily colonize new areas and diversify, or conversely, to extremely specialized phenotypes or heavily relictual climatic niches that result in strong geographic localization and limited diversification.
Journal Article