scholarly journals Quantitative histological models suggest endothermy in plesiosaurs

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4955 ◽  
Author(s):  
Corinna V. Fleischle ◽  
Tanja Wintrich ◽  
P. Martin Sander
Keyword(s):  
Growth Rates ◽  
Bone Growth ◽  
Global Radiation ◽  
Predictor Variable ◽  
Fast Growth ◽  
Late Triassic ◽  
Vascular Density ◽  
Metabolic Rates ◽  
Bone Apposition ◽  
Local Bone

BackgroundPlesiosaurs are marine reptiles that arose in the Late Triassic and survived to the Late Cretaceous. They have a unique and uniform bauplan and are known for their very long neck and hydrofoil-like flippers. Plesiosaurs are among the most successful vertebrate clades in Earth’s history. Based on bone mass decrease and cosmopolitan distribution, both of which affect lifestyle, indications of parental care, and oxygen isotope analyses, evidence for endothermy in plesiosaurs has accumulated. Recent bone histological investigations also provide evidence of fast growth and elevated metabolic rates. However, quantitative estimations of metabolic rates and bone growth rates in plesiosaurs have not been attempted before.MethodsPhylogenetic eigenvector maps is a method for estimating trait values from a predictor variable while taking into account phylogenetic relationships. As predictor variable, this study employs vascular density, measured in bone histological sections of fossil eosauropterygians and extant comparative taxa. We quantified vascular density as primary osteon density, thus, the proportion of vascular area (including lamellar infillings of primary osteons) to total bone area. Our response variables are bone growth rate (expressed as local bone apposition rate) and resting metabolic rate (RMR).ResultsOur models reveal bone growth rates and RMRs for plesiosaurs that are in the range of birds, suggesting that plesiosaurs were endotherm. Even for basal eosauropterygians we estimate values in the range of mammals or higher.DiscussionOur models are influenced by the availability of comparative data, which are lacking for large marine amniotes, potentially skewing our results. However, our statistically robust inference of fast growth and fast metabolism is in accordance with other evidence for plesiosaurian endothermy. Endothermy may explain the success of plesiosaurs consisting in their survival of the end-Triassic extinction event and their global radiation and dispersal.

Paleohistological estimation of bone growth rate in extinct archosaurs

Paleobiology ◽  
2012 ◽  
Vol 38 (2) ◽  
pp. 335-349 ◽  
Author(s):  
Jorge Cubo ◽  
Nathalie Le Roy ◽  
Cayetana Martinez-Maza ◽  
Laetitia Montes
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Bone Growth ◽  
Common Ancestor ◽  
Phylogenetic Signal ◽  
Growth Patterns ◽  
Last Common Ancestor ◽  
Metabolic Rates ◽  
Extant Species ◽  
Validation Tests

The clade Archosauria contains two very different sister groups in terms of diversity (number of species) and disparity (phenotypic variation): Crurotarsi (taxa more closely related to crocodiles than to birds) and Ornithodira (pterosaurs and dinosaurs including birds). The extant species of Crurotarsi may constitute a biased sample of past biodiversity regarding growth patterns and metabolic rates. Bone histological characters can be conserved over hundreds of millions of years in the fossil record and potentially contain information about individual age at death, age at sexual maturity, bone growth rates, and basal metabolic rates of extinct vertebrates. Using a sample of extant amniotes, we have constructed a paleobiological model to estimate bone growth rate from bone histological traits. Cross-validation tests show that this model is reliable. We then used it to estimate bone growth rates in a sample of extinct archosaurs including Crurotarsi and Ornithodira. After testing for phylogenetic signal, optimization of femoral growth rates through squared change parsimony onto a time-calibrated tree of amniotes shows two divergent evolutionary trends: whereas bone growth rates increase from the last common ancestor of Ornithodira to extant birds, they decrease from the last common ancestor of Crurotarsi to extant crocodiles. However, we conclude, on the basis of recent evidence for unidirectional airflow in the lungs of alligators, that crocodiles may have retained the capacity of growing at high rates.

Comparison of Aminocyclopyrachlor to Common Herbicides for Kudzu (Pueraria montana) Management

2011 ◽  
Vol 4 (4) ◽  
pp. 419-426 ◽  
Author(s):  
Patrick J. Minogue ◽  
Stephen F. Enloe ◽  
Anna Osiecka ◽  
Dwight K. Lauer
Keyword(s):  
Growth Rates ◽  
Groundwater Pollution ◽  
Fast Growth ◽  
Control Measures ◽  
Volume Index ◽  
Metsulfuron Methyl ◽  
Herbicide Treatment ◽  
Herbicide Treatments ◽  
Repeated Applications ◽  
Pueraria Montana

AbstractKudzu is an invasive perennial climbing vine characterized by fast growth rates and tolerance to control measures. Repeated applications with high rates of 2,4-D plus picloram provide effective kudzu control, but picloram use is not permitted in certain states due to groundwater pollution concerns. Studies were conducted in Alabama and Florida to compare kudzu control with aminocyclopyrachlor, a new herbicide, to control provided by aminopyralid, clopyralid, metsulfuron methyl, and picloram plus 2,4-D, which are common treatments for kudzu management. Two annual applications of the same herbicide treatment were evaluated for effects on kudzu cover, kudzu volume index, and cover of other vegetation. Aminocyclopyrachlor at 140 to 280 g ae ha−1 (2 to 4 oz ae ac−1) was as effective as the standard 4.48 kg ae ha−1 (4 lb ae ac−1) 2,4-D amine plus 1.2 kg ae ha−1 picloram for kudzu control. There were no differences in kudzu control among the three rates of aminocyclopyrachlor tested. Colonization by graminoids, forbs, and Rubus spp. at 2 yr was greatest for herbicides providing the best kudzu control: aminocyclopyrachlor, and 2,4-D plus picloram. Herbicide treatments were more effective in controlling kudzu at the Alabama location, but repeated annual applications for 2 yr did not completely eliminate kudzu with any treatment at either site.

scholarly journals Toward Smart Implant Synthesis: Bonding Bioceramics of Different Resorbability to Match Bone Growth Rates

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Rafael Comesaña ◽  
Fernando Lusquiños ◽  
Jesús del Val ◽  
Félix Quintero ◽  
Antonio Riveiro ◽  
...  
Keyword(s):  
Growth Rates ◽  
Bone Growth

Relationship between bone growth rate and bone tissue organization in amniotes: first test of Amprino's rule in a phylogenetic context

2010 ◽  
Vol 60 (1) ◽  
pp. 25-41 ◽  
Author(s):  
Jacques Castanet ◽  
Jorge Cubo ◽  
Laëtitia Montes
Keyword(s):  
Growth Rate ◽  
Bone Tissue ◽  
Growth Rates ◽  
Bone Growth ◽  
Phylogenetic Signal ◽  
Variation Partitioning ◽  
High Growth ◽  
Tissue Organization ◽  
Shared Ancestry ◽  
Functional Factors

AbstractA debate on the determinism (phylogenetic versus functional) of the diversity of bone histological features has centred the interest of bone comparative biologists. While some authors have noticed the presence of a phylogenetic signal in bone tissue variation, many others have argued that these characters may not include much phylogenetic information, but rather reflect functional factors. Here we quantify both components in a sample of amniotes. We hypothesize that: 1/ the observed variation is partly the outcome of shared ancestry (phylogenetic factor) and 2/ for a given quantity of bone produced, tissues formed at a rapid rate may have a higher fraction of vascular cavities than those produced at a slower rate (functional factor). Variation partitioning analyses show that the phylogeny explains a significant portion of the variation of bone vascularity (85.3%), bone growth rate also explains a significant portion of this variation (68.3%), and there is an important overlap (67.9%). Finally, an optimization through least-squares parsimony of bone growth rates onto the phylogeny shows that the most important evolutionary change may have occurred after the split between crocodiles and birds. This change may be linked to the origin of avian endothermic metabolism because high growth rates involve high protein turnover, which is very energy consuming. We conclude that the debate on the dichotomy between phylogenetic versus functional causation of bone histological diversity is misleading, because we have shown that bone vascularity has, at the same time, a functional significance and a phylogenetic signal.

scholarly journals Cytoplasmic and Periplasmic Proteomic Signatures of Exponentially Growing Cells of the Psychrophilic BacteriumPseudoalteromonas haloplanktisTAC125

2010 ◽  
Vol 77 (4) ◽  
pp. 1276-1283 ◽  
Author(s):  
Boris Wilmes ◽  
Holger Kock ◽  
Susanne Glagla ◽  
Dirk Albrecht ◽  
Birgit Voigt ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Growth Rates ◽  
Stress Proteins ◽  
High Capacity ◽  
Tca Cycle ◽  
Fast Growth ◽  
Natural Environments ◽  
Permissive Temperature ◽  
Moderate Growth

ABSTRACTThe psychrophilic model bacteriumPseudoalteromonas haloplanktisis characterized by remarkably fast growth rates under low-temperature conditions in a range from 5°C to 20°C. In this study the proteome of cellular compartments, the cytoplasm and periplasm, ofP. haloplanktisstrain TAC125 was analyzed under exponential growth conditions at a permissive temperature of 16°C. By means of two-dimensional protein gel electrophoresis and mass spectrometry, a first inventory of the most abundant cytoplasmic and periplasmic proteins expressed in a peptone-supplemented minimal medium was established. By this approach major enzymes of the amino acid catabolism of this marine bacterium could be functionally deduced. The cytoplasmic proteome showed a predominance of amino acid degradation pathways and tricarboxylic acid (TCA) cycle enzymes but also the protein synthesis machinery. Furthermore, high levels of cold acclimation and oxidative stress proteins could be detected at this moderate growth temperature. The periplasmic proteome was characterized by a significant abundance of transporters, especially of highly expressed putative TonB-dependent receptors. This high capacity for protein synthesis, efficient amino acid utilization, and substrate transport may contribute to the fast growth rates of the copiotrophic bacteriumP. haloplanktisin its natural environments.

ℵ0-categorical structures with arbitrarily fast growth of algebraic closure

2002 ◽  
Vol 67 (3) ◽  
pp. 897-909
Author(s):  
David M. Evans ◽  
M. E. Pantano
Keyword(s):  
Growth Rate ◽  
Automorphism Group ◽  
Finite Subset ◽  
Growth Rates ◽  
Algebraic Closure ◽  
Fast Growth ◽  
Permutation Groups ◽  
Natural Numbers ◽  
Categorical Structure ◽  
Image Position

Various results have been proved about growth rates of certain sequences of integers associated with infinite permutation groups. Most of these concern the number of orbits of the automorphism group of an ℵ0-categorical structure on the set of unordered n-subsets or on the set of n-tuples of elements of . (Recall that by the Ryll-Nardzewski Theorem, if is countable and ℵ0-categorical, the number of the orbits of its automorphism group Aut() on the set of n-tuples from is finite and equals the number of complete n-types consistent with the theory of .) The book [Ca90] is a convenient reference for these results. One of the oldest (in the realms of ‘folklore’) is that for any sequence (Kn)n∈ℕ of natural numbers there is a countable ℵ0-categorical structure such that the number of orbits of Aut() on the set of n-tuples from is greater than kn for all n.These investigations suggested the study of the growth rate of another sequence. Let be an ℵ0-categorical structure and X be a finite subset of . Let acl(X) be the algebraic closure of X, that is, the union of the finite X-definable subsets of . Equivalently, this is the union of the finite orbits on of Aut()(X), the pointwise stabiliser of X in Aut(). Define

Crystal Growth Rates in Doped SbxTe Fast-Growth Phase-Change Films Studied with Transmission Electron Microscopy

2008 ◽  
Vol 1072 ◽  
Author(s):  
Bart J. Kooi ◽  
Ramanathaswamy Pandian ◽  
Jeff Th. M. De Hosson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystal Growth ◽  
Phase Change ◽  
Growth Phase ◽  
Growth Rates ◽  
Fast Growth ◽  
Various Boundary Conditions ◽  
Dielectric Layers ◽  
Transmission Electron

ABSTRACTIsothermal crystallization of doped SbxTe fast-growth phase-change films was investigated using transmission electron microscopy with in situ heating. SbxTe films with four different values for the Sb/Te ratio, x=3.0, 3.3, 3.6 and 4.2, were analyzed and the films were sandwiched between two types of dielectric layers. One dielectric layer type is based on 80at.%ZnS-20at.%SiO2, the other on (Ge,Cr)N. The crystal growth rates reduce if the phase-change films are sandwiched between amorphous dielectric layers. The reduction is very pronounced at the lowest measured temperatures (150 °C), becomes smaller at higher temperatures and probably disappears at around 200 °C. The crystal growth rates increase with increasing Sb/Te ratio, but the activation energy for crystal growth is not significantly affected by the Sb/Te ratio. Finally a systematic study of the effect of the electron beam of the TEM on the crystal growth rates is performed showing accelerated growth rates. The present work shows that particularly at relative low temperatures, just above the glass-transition temperature, the growth rates as limited by the atomic mobilities are sensitive to various (boundary) conditions, e.g. capping layers and irradiation.

scholarly journals The basis of antagonistic pleiotropy in hfq mutations that have opposite effects on fitness at slow and fast growth rates

Heredity ◽  
2012 ◽  
Vol 110 (1) ◽  
pp. 10-18 ◽  
Author(s):  
R Maharjan ◽  
C McKenzie ◽  
A Yeung ◽  
T Ferenci
Keyword(s):  
Growth Rates ◽  
Fast Growth ◽  
Antagonistic Pleiotropy
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