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https://www.readbyqxmd.com/read/28296327/fricke-gel-dosimeter-with-improved-sensitivity-for-low-dose-level-measurements
#1
Mauro Vaiente, Wladimir Molina, Lila Carrizales Silva, Rodolfo Figueroa, Francisco Malano, Pedro Pérez, Mauricio Santibañez, José Vedelago
Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue-equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, independence of dose rate and incident direction, as well as linear dose response. This work presents the development and characterization of an improved Fricke gel system, based on modified chemical compositions, making possible its application in clinical radiology due to its improved sensitivity...
July 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28289222/fossil-and-genomic-evidence-constrains-the-timing-of-bison-arrival-in-north-america
#2
Duane Froese, Mathias Stiller, Peter D Heintzman, Alberto V Reyes, Grant D Zazula, André E R Soares, Matthias Meyer, Elizabeth Hall, Britta J L Jensen, Lee J Arnold, Ross D E MacPhee, Beth Shapiro
The arrival of bison in North America marks one of the most successful large-mammal dispersals from Asia within the last million years, yet the timing and nature of this event remain poorly determined. Here, we used a combined paleontological and paleogenomic approach to provide a robust timeline for the entry and subsequent evolution of bison within North America. We characterized two fossil-rich localities in Canada's Yukon and identified the oldest well-constrained bison fossil in North America, a 130,000-y-old steppe bison, Bison cf...
March 13, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28276513/widespread-platinum-anomaly-documented-at-the-younger-dryas-onset-in-north-american-sedimentary-sequences
#3
Christopher R Moore, Allen West, Malcolm A LeCompte, Mark J Brooks, I Randolph Daniel, Albert C Goodyear, Terry A Ferguson, Andrew H Ivester, James K Feathers, James P Kennett, Kenneth B Tankersley, A Victor Adedeji, Ted E Bunch
Previously, a large platinum (Pt) anomaly was reported in the Greenland ice sheet at the Younger Dryas boundary (YDB) (12,800 Cal B.P.). In order to evaluate its geographic extent, fire-assay and inductively coupled plasma mass spectrometry (FA and ICP-MS) elemental analyses were performed on 11 widely separated archaeological bulk sedimentary sequences. We document discovery of a distinct Pt anomaly spread widely across North America and dating to the Younger Dryas (YD) onset. The apparent synchroneity of this widespread YDB Pt anomaly is consistent with Greenland Ice Sheet Project 2 (GISP2) data that indicated atmospheric input of platinum-rich dust...
March 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28276199/new-insights-into-a-hot-environment-for-early-life
#4
REVIEW
Jianghong Dai
Investigating the physical-chemical setting of early life is a challenging task. In this contribution, I attempt to introduce a provocative concept from cosmology-cosmic microwave background (CMB), which is the residual thermal radiation from a hot early Universe-to the field. For this purpose, I revisit a recently deduced biomarker, the 1,6-anhydro bond of sugars in bacteria. In vitro, the 1,6-anhydro bond of sugars reflects and captures residual thermal radiation in thermochemical processes and therefore is somewhat analogous to CMB...
March 9, 2017: Environmental Microbiology Reports
https://www.readbyqxmd.com/read/28265519/specimen-level-phylogenetics-in-paleontology-using-the-fossilized-birth-death-model-with-sampled-ancestors
#5
Andrea Cau
Bayesian phylogenetic methods integrating simultaneously morphological and stratigraphic information have been applied increasingly among paleontologists. Most of these studies have used Bayesian methods as an alternative to the widely-used parsimony analysis, to infer macroevolutionary patterns and relationships among species-level or higher taxa. Among recently introduced Bayesian methodologies, the Fossilized Birth-Death (FBD) model allows incorporation of hypotheses on ancestor-descendant relationships in phylogenetic analyses including fossil taxa...
2017: PeerJ
https://www.readbyqxmd.com/read/28196688/biodiversity-and-topographic-complexity-modern-and-geohistorical-perspectives
#6
REVIEW
Catherine Badgley, Tara M Smiley, Rebecca Terry, Edward B Davis, Larisa R G DeSantis, David L Fox, Samantha S B Hopkins, Tereza Jezkova, Marjorie D Matocq, Nick Matzke, Jenny L McGuire, Andreas Mulch, Brett R Riddle, V Louise Roth, Joshua X Samuels, Caroline A E Strömberg, Brian J Yanites
Topographically complex regions on land and in the oceans feature hotspots of biodiversity that reflect geological influences on ecological and evolutionary processes. Over geologic time, topographic diversity gradients wax and wane over millions of years, tracking tectonic or climatic history. Topographic diversity gradients from the present day and the past can result from the generation of species by vicariance or from the accumulation of species from dispersal into a region with strong environmental gradients...
March 2017: Trends in Ecology & Evolution
https://www.readbyqxmd.com/read/28187191/empirical-and-bayesian-approaches-to-fossil-only-divergence-times-a-study-across-three-reptile-clades
#7
Alan H Turner, Adam C Pritchard, Nicholas J Matzke
Estimating divergence times on phylogenies is critical in paleontological and neontological studies. Chronostratigraphically-constrained fossils are the only direct evidence of absolute timing of species divergence. Strict temporal calibration of fossil-only phylogenies provides minimum divergence estimates, and various methods have been proposed to estimate divergences beyond these minimum values. We explore the utility of simultaneous estimation of tree topology and divergence times using BEAST tip-dating on datasets consisting only of fossils by using relaxed morphological clocks and birth-death tree priors that include serial sampling (BDSS) at a constant rate through time...
2017: PloS One
https://www.readbyqxmd.com/read/28181330/discrete-and-morphometric-traits-reveal-contrasting-patterns-and-processes-in-the-macroevolutionary-history-of-a-clade-of-scorpions
#8
N Mongiardino Koch, F S Ceccarelli, A A Ojanguren-Affilastro, M J Ramírez
Many palaeontological studies have investigated the evolution of entire body plans, generally relying on discrete character-taxon matrices. In contrast, macroevolutionary studies performed by neontologists have mostly focused on morphometric traits. Although these data types are very different, some studies have suggested that they capture common patterns. Nonetheless, the tests employed to support this claim have not explicitly incorporated a phylogenetic framework and may therefore be susceptible to confounding effects due to the presence of common phylogenetic structure...
February 9, 2017: Journal of Evolutionary Biology
https://www.readbyqxmd.com/read/28148209/paleontological-studies-integrated-into-a-new-evolutionary-zoology
#9
Shigeru Kuratani, Takema Fukatsu
Zoological Letters, an open access online journal launched in 2015 is entering its third year of publication, and now seeks to drive new insights in evolutionary and comparative zoology by the inclusion of paleontological studies into its scope.
February 2017: Zoological Science
https://www.readbyqxmd.com/read/28111950/expansion-for-the-brachylophosaurus-canadensis-collagen-i-sequence-and-additional-evidence-of-the-preservation-of-cretaceous-protein
#10
Elena R Schroeter, Caroline J DeHart, Timothy P Cleland, Wenxia Zheng, Paul M Thomas, Neil L Kelleher, Marshall Bern, Mary H Schweitzer
Sequence data from biomolecules such as DNA and proteins, which provide critical information for evolutionary studies, have been assumed to be forever outside the reach of dinosaur paleontology. Proteins, which are predicted to have greater longevity than DNA, have been recovered from two nonavian dinosaurs, but these results remain controversial. For proteomic data derived from extinct Mesozoic organisms to reach their greatest potential for investigating questions of phylogeny and paleobiology, it must be shown that peptide sequences can be reliably and reproducibly obtained from fossils and that fragmentary sequences for ancient proteins can be increasingly expanded...
February 3, 2017: Journal of Proteome Research
https://www.readbyqxmd.com/read/28107398/integrated-chronology-flora-and-faunas-and-paleoecology-of-the-alajuela-formation-late-miocene-of-panama
#11
Bruce J MacFadden, Douglas S Jones, Nathan A Jud, Jorge W Moreno-Bernal, Gary S Morgan, Roger W Portell, Victor J Perez, Sean M Moran, Aaron R Wood
The late Miocene was an important time to understand the geological, climatic, and biotic evolution of the ancient New World tropics and the context for the Great American Biotic Interchange (GABI). Despite this importance, upper Miocene deposits containing diverse faunas and floras and their associated geological context are rare in Central America. We present an integrated study of the geological and paleontological context and age of a new locality from Lago Alajuela in northern Panama (Caribbean side) containing late Miocene marine and terrestrial fossils (plants, invertebrates, and vertebrates) from the Alajuela Formation...
2017: PloS One
https://www.readbyqxmd.com/read/28073604/morphometric-and-genetic-analysis-of-arcella-intermedia-and-arcella-intermedia-laevis-amoebozoa-arcellinida-illuminate-phenotypic-plasticity-in-microbial-eukaryotes
#12
Alfredo L Porfírio-Sousa, Giulia M Ribeiro, Daniel J G Lahr
Testate amoebae are eukaryotic microorganisms characterized by the presence of an external shell (test). The shell morphology is used as a diagnostic character, but discordance between morphological and molecular data has been demonstrated in groups of arcellinids (Amoebozoa), one of the principal groups of testate amoebae. Morphology of the test is supposed to differentiate genera and species and it is applied in ecological, monitoring and paleontological studies. However, if phenotype does not reflect genotype, conclusions in these types of studies become severely impaired...
November 25, 2016: European Journal of Protistology
https://www.readbyqxmd.com/read/28028456/seqenv-linking-sequences-to-environments-through-text-mining
#13
Lucas Sinclair, Umer Z Ijaz, Lars Juhl Jensen, Marco J L Coolen, Cecile Gubry-Rangin, Alica Chroňáková, Anastasis Oulas, Christina Pavloudi, Julia Schnetzer, Aaron Weimann, Ali Ijaz, Alexander Eiler, Christopher Quince, Evangelos Pafilis
Understanding the distribution of taxa and associated traits across different environments is one of the central questions in microbial ecology. High-throughput sequencing (HTS) studies are presently generating huge volumes of data to address this biogeographical topic. However, these studies are often focused on specific environment types or processes leading to the production of individual, unconnected datasets. The large amounts of legacy sequence data with associated metadata that exist can be harnessed to better place the genetic information found in these surveys into a wider environmental context...
2016: PeerJ
https://www.readbyqxmd.com/read/28012461/ten-years-in-the-dump-an-updated-review-of-the-miocene-primate-bearing-localities-from-abocador-de-can-mata-ne-iberian-peninsula
#14
David M Alba, Isaac Casanovas-Vilar, Miguel Garcés, Josep M Robles
More than ten years of paleontological fieldwork during the enlargement of the Can Mata Landfill (Abocador de Can Mata [ACM]), in els Hostalets de Pierola (Vallès-Penedès Basin, NE Iberian Peninsula) led to the recovery of >60,000 Miocene vertebrate remains. The huge sampling effort (due to continuous surveillance of heavy machinery digging activity, coupled with manual excavation and screen-washing of sediments) enabled generally rare faunal elements such as pliopithecoid and hominoid primates to be found...
January 2017: Journal of Human Evolution
https://www.readbyqxmd.com/read/28004894/explanations-for-adaptations-just-so-stories-and-limitations-on-evidence-in-evolutionary-biology
#15
Richard J Smith
Explanations of the historical origin of specific individual traits are a key part of the research program in paleontology and evolutionary biology. Why did bipedalism evolve in the human lineage? Why did some dinosaurs and related species have head crests? Why did viviparity evolve in some reptiles? Why did the common ancestor of primates evolve stereoscopic vision, grasping hands and feet, nails instead of claws, and large brains? These are difficult questions. To varying degrees, an explanation must grapple with (1) judgments about changes in fitness that might follow from a change in morphology - without actually observing behavior or measuring reproductive success, (2) the relationship between genes and traits, (3) limitations on doing relevant experiments, (4) the interpretation of causes that are almost certainly contingent, multifactorial, interactive, hierarchical, nonlinear, emergent, and probabilistic rather than deterministic, (5) limited information about variation and ontogeny, (6) a dataset based on the random fortunes of the historical record, including only partial hard-tissue morphology and no soft-tissue morphology, (7) an equally partial and problematic (for example, time-averaged) record of the environment, (8) the compression of all data into a geological time scale that is likely to miss biologically important events or fluctuations, (9) dependence on a process that can only be inferred ("form and even behavior may leave fossil traces, but forces like natural selection do not", (1:130) ) and finally, (10) the assumption of the "adaptationist programme"(2) that the trait in question is in fact an adaptation rather than a consequence of genetic drift, correlated evolution, pleiotropy, exaptation, or other mechanisms...
November 2016: Evolutionary Anthropology
https://www.readbyqxmd.com/read/28003534/dental-data-perform-relatively-poorly-in-reconstructing-mammal-phylogenies-morphological-partitions-evaluated-with-molecular-benchmarks
#16
Robert S Sansom, Matthew Albion Wills, Tamara Williams
Phylogenetic trees underpin reconstructions of evolutionary history and tests of evolutionary hypotheses. They are inferred from both molecular and morphological data, yet the relative value of morphology has been questioned in this context due to perceived homoplasy, developmental linkage, and non-independence of characters. Nevertheless, fossil data are limited to incomplete subsets of preserved morphology, and different regions are treated as equivalent. Through meta-analysis of 40 datasets, we show here that the dental and osteological characters of mammals convey significantly different phylogenetic signals, and that osteological characters are significantly more compatible with molecular trees...
December 20, 2016: Systematic Biology
https://www.readbyqxmd.com/read/28000409/the-evolution-of-the-zygomatic-bone-from-agnatha-to-tetrapoda
#17
Zhikun Gai, Xiaobo Yu, Min Zhu
Establishing the homology of the zygomatic or jugal bone and tracing its origin and early evolution represents a complex issue because of large morphological gaps between various groups of vertebrates. Using recent paleontological findings, we discuss the deep homology of the zygomatic or jugal bone in stem gnathostomes (placoderms) and examine its homology and modifications in crown gnathostomes (acanthodians, chondrichthyans and osteichthyans). The discovery of the placoderm Entelognathus from the Silurian of China (∼423 million years ago) established that the large dermal plates in placoderms and osteichthyans are homologous...
January 2017: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
https://www.readbyqxmd.com/read/27940618/from-teeth-to-baleen-and-raptorial-to-bulk-filter-feeding-in-mysticete-cetaceans-the-role-of-paleontological-genetic-and-geochemical-data-in-feeding-evolution-and-ecology
#18
Annalisa Berta, Agnese Lanzetti, Eric G Ekdale, Thomas A Deméré
The origin of baleen and filter feeding in mysticete cetaceans occurred sometime between approximately 34 and 24 million years ago and represents a major macroevolutionary shift in cetacean morphology (teeth to baleen) and ecology (raptorial to filter feeding). We explore this dramatic change in feeding strategy by employing a diversity of tools and approaches: morphology, molecules, development, and stable isotopes from the geological record. Adaptations for raptorial feeding in extinct toothed mysticetes provide the phylogenetic context for evaluating morphological apomorphies preserved in the skeletons of stem and crown edentulous mysticetes...
December 2016: Integrative and Comparative Biology
https://www.readbyqxmd.com/read/27939713/incorporating-fossils-into-hypotheses-of-insect-phylogeny
#19
REVIEW
Jessica L Ware, Phillip Barden
Fossils represent stem and crown lineages, and their inclusion in phylogenetic reconstruction influences branch lengths, topology, and divergence time estimation. In addition, paleontological data may inform trends in morphological evolution as well as biogeographic history. Here we review the incorporation of fossils in studies of insect evolution, from morphological analyses to combined 'total evidence' node dating analyses. We discuss challenges associated with fossil based phylogenetics, and suggest best practices for use in tree reconstruction...
December 2016: Current Opinion in Insect Science
https://www.readbyqxmd.com/read/27917244/la-images-a-software-for-elemental-distribution-bioimaging-using-la-icp-ms-data
#20
Hugo López-Fernández, Gustavo de S Pessôa, Marco A Z Arruda, José L Capelo-Martínez, Florentino Fdez-Riverola, Daniel Glez-Peña, Miguel Reboiro-Jato
The spatial distribution of chemical elements in different types of samples is an important field in several research areas such as biology, paleontology or biomedicine, among others. Elemental distribution imaging by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is an effective technique for qualitative and quantitative imaging due to its high spatial resolution and sensitivity. By applying this technique, vast amounts of raw data are generated to obtain high-quality images, essentially making the use of specific LA-ICP-MS imaging software that can process such data absolutely mandatory...
2016: Journal of Cheminformatics
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