161 research outputs found
Comprehensive School Guidance Programs in Nebraska: Implications for Rural Schools
Archival data from an in-state survey of 428 elementary and secondary school counselors completed by the Nebraska Department of Education regarding comprehensive guidance programs was reviewed for relevant information. This information is discussed relative to the current views and knowledge regarding the state of comprehensive developmental guidance and their implications for school counselors and administrators
A bittern (Aves: Ardeidae) from the Early Miocene of New Zealand
Author version made available in accordance with Publisher copyright policy
Early Miocene fossil frogs (Anura: Leiopelmatidae) from New Zealand.
Author version made available in accordance with publisher copyright policy.The first pre-Quaternary anurans from New Zealand are reported from the Early Miocene (19–16 Ma) St Bathans Fauna based on 10 fossil bones. Four bones representing two new species differing in size are described in Leiopelma: Leiopelmatidae, and are the first Tertiary records for the family. Six indeterminate frog fossils are morphologically similar to leiopelmatids and represent two species consistent in size with those known from diagnostic material. These records are highly significant, as minimally, they reduce the duration of the leiopelmatid ‘ghost lineage’ by c.20 million years and demonstrate that a diversity of leiopelmatids has long been present on New Zealand, supporting the ancient dichotomy of the extant species based on molecular data
A new Eocene species of presbyornithid (Aves, Anseriformes) from Murgon, Australia
The taxa found in an Eocene deposit, near Murgon, Queensland, the only pre-Oligocene Paleogene site recording a terrestrial vertebrate fauna from Australia, are very significant for the insight they provide concerning the evolution of the Australian biota. Here we resolve the identity of fossils previously referred to the Graculavidae, waterbirds of then unresolved affinities. We taxonomically describe the first bird to be named from this fauna, Murgonornis archeri gen. et sp. nov., Presbyornithidae. Our findings reveal that presbyornithids were widespread globally in the earliest Eocene, and that this family had a history on Australia from at least 55 Ma until ca. 24 Ma, when they disappear from the fossil record
The unexpected survival of an ancient lineage of anseriform birds into the Neogene of Australia: the youngest record of Presbyornithidae
. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.Presbyornithids were the dominant birds in Palaeogene lacustrine assemblages, especially in the Northern Hemisphere, but are thought to have disappeared worldwide by the mid-Eocene. Now classified within Anseriformes (screamers, ducks, swans and geese), their relationships have long been obscured by their strange wader-like skeletal morphology. Reassessment of the late Oligocene South Australian material attributed to Wilaru tedfordi, long considered to be of a stone-curlew (Burhinidae, Charadriiformes), reveals that this taxon represents the first record of a presbyornithid in Australia. We also describe the larger Wilaru prideauxi sp. nov. from the early Miocene of South Australia, showing that presbyornithids survived in Australia at least until ca 22 Ma. Unlike on other continents, where presbyornithids were replaced by aquatic crown-group anatids (ducks, swans and geese), species of Wilaru lived alongside these waterfowl in Australia. The morphology of the tarsometatarsus of these species indicates that, contrary to other presbyornithids, they were predominantly terrestrial birds, which probably contributed to their long-term survival in Australia. The morphological similarity between species of Wilaru and the Eocene South American presbyornithid Telmabates antiquus supports our hypothesis of a Gondwanan radiation during the evolutionary history of the Presbyornithidae. Teviornis gobiensis from the Late Cretaceous of Mongolia is here also reassessed and confirmed as a presbyornithid. These findings underscore the temporal continuance of Australia’s vertebrates and provide a new context in which the phylogeny and evolutionary history of presbyornithids can be examined
Miocene fossils show that kiwi (Apteryx, Apterygidae) are probably not phyletic dwarves
Copyright 2013 © Verlag Naturhistorisches Museum. Published version of the paper reproduced here with permission from the publisher. Publisher website: http://www.nhm-wien.ac.at/Until now, kiwi (Apteryx, Apterygidae) have had no pre-Quaternary fossil record to inform on the
timing of their arrival in New Zealand or on their inter-ratite relationships. Here we describe two fossils in a new
genus of apterygid from Early Miocene sediments at St Bathans, Central Otago, minimally dated to 19–16 Ma.
The new fossils indicate a markedly smaller and possibly volant bird, supporting a possible overwater dispersal
origin to New Zealand of kiwi independent of moa. If the common ancestor of this early Miocene apterygid species
and extant kiwi was similarly small and volant, then the phyletic dwarfing hypothesis to explain relatively
small body size of kiwi compared with other ratites is incorrect. Apteryx includes five extant species distributed
on North, South, Stewart and the nearshore islands of New Zealand. They are nocturnal, flightless and comparatively
large birds, 1–3 kg, with morphological attributes that reveal an affinity with ratites, but others, such as
their long bill, that differ markedly from all extant members of that clade. Although kiwi were long considered
most closely related to sympatric moa (Dinornithiformes), all recent analyses of molecular data support a closer
affinity to Australian ratites (Casuariidae). Usually assumed to have a vicariant origin in New Zealand (ca 80–60
Ma), a casuariid sister group relationship for kiwi, wherein the common ancestor was volant, would more easily
allow a more recent arrival via overwater dispersal
On the taxonomic composition and phylogenetic affinities of the recently proposed clade Vegaviidae Agnolín et al., 2017 ‒ neornithine birds from the Upper Cretaceous of the Southern Hemisphere
© 2018 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/
This author accepted manuscript is made available following 24 month embargo from date of publication (Feb 2018) in accordance with the publisher’s archiving policyPolarornis and Vegavis from the Upper Cretaceous of Antarctica are among the few Mesozoic birds from the Southern Hemisphere. In the original descriptions, they were assigned to two widely disparate avian clades, that is, Gaviiformes and crown group Anseriformes, respectively. In a recent publication, however, specimens referred to both taxa were classified into a new higher-level taxon, Vegaviidae, to which various other late Mesozoic and early Cenozoic avian taxa were also assigned. Here, we detail that classification into Vegaviidae is poorly supported for most of these latter fossils, which is particularly true for Australornis lovei and an unnamed phaethontiform fossil from the Waipara Greensand in New Zealand. Plesiomorphic traits of the pterygoid and the mandible clearly show that Vegavis is not a representative of crown group Anseriformes, and we furthermore point out that even anseriform or galloanserine affinities of Vegaviidae have not been firmly established
History Repeats: Large Scale Synchronous Biological Turnover in Avifauna From the Plio-Pleistocene and Late Holocene of New Zealand
New Zealand's unique biodiversity is the product of at least 55 million years of geographic isolation, supplemented by persistent transoceanic migration. Palaeontological and genetic evidence suggest most New Zealand avifauna has colonized from Australia. We synthesize evolutionary genetic studies to show a previously unrecognized clustering of divergence times in Australian and New Zealand bird species pairs, across the avian phylogeny at the beginning of the Pleistocene, around 2.5 million years ago. The timing coincides with major climatic and vegetation changes with the initiation of the Plio-Pleistocene glacial cycles. Recent anthropogenic impacts and environmental modifications are replicating in some important ways Pleistocene glacial landscapes, resulting in a new wave of avian “native invaders” into New Zealand
miRNAome analysis of the mammalian neuronal nicotinic acetylcholine receptor gene family
Nicotine binds to and activates a family of ligand-gated ion channels, neuronal nicotinic acetylcholine receptors (nAChRs). Chronic nicotine exposure alters the expression of various nAChR subtypes, which likely contributes to nicotine dependence; however, the underlying mechanisms regulating these changes remain unclear. A growing body of evidence indicates that microRNAs (miRNAs) may be involved in nAChR regulation. Using bioinformatics, miRNA library screening, site-directed mutagenesis, and gene expression analysis, we have identified a limited number of miRNAs that functionally interact with the 3\u27-untranslated regions (3\u27 UTRs) of mammalian neuronal nAChR subunit genes. In silico analyses revealed specific, evolutionarily conserved sites within the 3\u27 UTRs through which the miRNAs regulate gene expression. Mutating these sites disrupted miRNA regulation confirming the in silico predictions. In addition, the miRNAs that target nAChR 3\u27 UTRs are expressed in mouse brain and are regulated by chronic nicotine exposure. Furthermore, we show that expression of one of these miRNAs, miR-542-3p, is modulated by nicotine within the mesocorticolimbic reward pathway. Importantly, overexpression of miR-542-3p led to a decrease in the protein levels of its target, the nAChR beta2 subunit. Bioinformatic analysis suggests that a number of the miRNAs play a general role in regulating cholinergic signaling. Our results provide evidence for a novel mode of nicotine-mediated regulation of the mammalian nAChR gene family
miRNAome analysis of the mammalian neuronal nicotinic acetylcholine receptor gene family
Nicotine binds to and activates a family of ligand-gated ion channels, neuronal nicotinic acetylcholine receptors (nAChRs). Chronic nicotine exposure alters the expression of various nAChR subtypes, which likely contributes to nicotine dependence; however, the underlying mechanisms regulating these changes remain unclear. A growing body of evidence indicates that microRNAs (miRNAs) may be involved in nAChR regulation. Using bioinformatics, miRNA library screening, site-directed mutagenesis, and gene expression analysis, we have identified a limited number of miRNAs that functionally interact with the 3\u27-untranslated regions (3\u27 UTRs) of mammalian neuronal nAChR subunit genes. In silico analyses revealed specific, evolutionarily conserved sites within the 3\u27 UTRs through which the miRNAs regulate gene expression. Mutating these sites disrupted miRNA regulation confirming the in silico predictions. In addition, the miRNAs that target nAChR 3\u27 UTRs are expressed in mouse brain and are regulated by chronic nicotine exposure. Furthermore, we show that expression of one of these miRNAs, miR-542-3p, is modulated by nicotine within the mesocorticolimbic reward pathway. Importantly, overexpression of miR-542-3p led to a decrease in the protein levels of its target, the nAChR beta2 subunit. Bioinformatic analysis suggests that a number of the miRNAs play a general role in regulating cholinergic signaling. Our results provide evidence for a novel mode of nicotine-mediated regulation of the mammalian nAChR gene family
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