scholarly journals Reptile-like physiology in Early Jurassic stem-mammals

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Elis Newham ◽  
Pamela G. Gill ◽  
Philippa Brewer ◽  
Michael J. Benton ◽  
Vincent Fernandez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Tomographic Imaging ◽  
Early Jurassic ◽  
Metabolic Rates ◽  
Metabolic Evolution ◽  
Flow Rates ◽  
X Ray ◽  
Nutrient Foramina ◽  
Physiological Evolution ◽  
Maximum Metabolic Rate

Abstract Despite considerable advances in knowledge of the anatomy, ecology and evolution of early mammals, far less is known about their physiology. Evidence is contradictory concerning the timing and fossil groups in which mammalian endothermy arose. To determine the state of metabolic evolution in two of the earliest stem-mammals, the Early Jurassic Morganucodon and Kuehneotherium, we use separate proxies for basal and maximum metabolic rate. Here we report, using synchrotron X-ray tomographic imaging of incremental tooth cementum, that they had maximum lifespans considerably longer than comparably sized living mammals, but similar to those of reptiles, and so they likely had reptilian-level basal metabolic rates. Measurements of femoral nutrient foramina show Morganucodon had blood flow rates intermediate between living mammals and reptiles, suggesting maximum metabolic rates increased evolutionarily before basal metabolic rates. Stem mammals lacked the elevated endothermic metabolism of living mammals, highlighting the mosaic nature of mammalian physiological evolution.

scholarly journals Reptile-like physiology in Early Jurassic stem-mammals

2019 ◽  
Author(s):  
Elis Newham ◽  
Pamela G. Gill ◽  
Philippa Brewer ◽  
Michael J. Benton ◽  
Vincent Fernandez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Metabolic Rate ◽  
Early Jurassic ◽  
Metabolic Rates ◽  
Fossil Species ◽  
X Ray Imaging ◽  
Femoral Blood Flow ◽  
Femoral Blood ◽  
Key Aspects ◽  
Maximum Metabolic Rate

AbstractThere is uncertainty regarding the timing and fossil species in which mammalian endothermy arose, with few studies of stem-mammals on key aspects of endothermy such as basal or maximum metabolic rates, or placing them in the context of living vertebrate metabolic ranges. Synchrotron X-ray imaging of incremental tooth cementum shows two Early Jurassic stem-mammals, Morganucodon and Kuehneotherium, had lifespans (a basal metabolic rate proxy) considerably longer than comparably sized living mammals, but similar to reptiles. Morganucodon also had femoral blood flow rates (a maximum metabolic rate proxy) intermediate between living mammals and reptiles. This shows maximum metabolic rates increased evolutionarily before basal rates, and that contrary to previous suggestions of a Triassic origin, Early Jurassic stem-mammals lacked the endothermic metabolism of living mammals.One Sentence SummarySurprisingly long lifespans and low femoral blood flow suggest reptile-like physiology in key Early Jurassic stem-mammals.

scholarly journals High Blood Flow Into the Femur Indicates Elevated Aerobic Capacity in Synapsids Since the Synapsida-Sauropsida Split

2021 ◽  
Vol 9 ◽  
Author(s):  
Philipp L. Knaus ◽  
Anneke H. van Heteren ◽  
Jacqueline K. Lungmus ◽  
P. Martin Sander
Keyword(s):  
Blood Flow ◽  
Metabolic Rate ◽  
Aerobic Capacity ◽  
Second Step ◽  
Metabolic Rates ◽  
Sectional Area ◽  
Cross Sectional ◽  
Femoral Length ◽  
Plesiomorphic State ◽  
Maximum Metabolic Rate

Varanids are the only non-avian sauropsids that are known to approach the warm-blooded mammals in stamina. Furthermore, a much higher maximum metabolic rate (MMR) gives endotherms (including birds) higher stamina than crocodiles, turtles, and non-varanid lepidosaurs. This has led researchers to hypothesize that mammalian endothermy evolved as a second step after the acquisition of elevated MMR in non-mammalian therapsids from a plesiomorphic state of low metabolic rates. In recent amniotes, MMR correlates with the index of blood flow into the femur (Qi), which is calculated from femoral length and the cross-sectional area of the nutrient foramen. Thus, Qi may serve as an indicator of MMR range in extinct animals. Using the Qi proxy and phylogenetic eigenvector maps, here we show that elevated MMRs evolved near the base of Synapsida. Non-mammalian synapsids, including caseids, edaphosaurids, sphenacodontids, dicynodonts, gorgonopsids, and non-mammalian cynodonts, show Qi values in the range of recent endotherms and varanids, suggesting that raised MMRs either evolved in synapsids shortly after the Synapsida-Sauropsida split in the Mississippian or that the low MMR of lepidosaurs and turtles is apomorphic, as has been postulated for crocodiles.

Mixing of Angiographic Contrast With Blood During Injections in the Cerebral Circulation

2008 ◽  
Author(s):  
Chander Sadasivan ◽  
Liliana Cesar ◽  
Baruch B. Lieber
Keyword(s):  
Blood Flow ◽  
Cerebral Circulation ◽  
Cerebral Aneurysms ◽  
Indicator Dilution ◽  
Parametric Imaging ◽  
Flow Rates ◽  
X Ray ◽  
The Past ◽  
First Pass ◽  
Concentration Curves

In the past, various techniques such as indicator dilution, transit time, parametric imaging, or first-pass distribution have been used to estimate blood flow rates during angiographic contrast injections. We have previously employed the method of modeling contrast concentration curves to assess changes in flow exchange between parent cerebral vessels and cerebral aneurysms due to endovascular treatment by flow divertors [1]. There has been concern, however, that contrast injected under such situations may remain as a separate slug or stream flowing with blood or that contrast may settle from blood in the direction of gravity due to its higher density [2,3]. According to this argument, therefore, the analysis of the transport of angiographic contrast visualized under X-ray cannot be used to represent the transport of blood.

scholarly journals Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Crystal Size ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

An anti-settling sample delivery instrument for serial femtosecond crystallography

2012 ◽  
Vol 45 (4) ◽  
pp. 674-678 ◽  
Author(s):  
Lukas Lomb ◽  
Jan Steinbrener ◽  
Sadia Bari ◽  
Daniel Beisel ◽  
Daniel Berndt ◽  
...  
Keyword(s):  
Constant Flow ◽  
Syringe Pump ◽  
Experimental Conditions ◽  
Flow Rates ◽  
X Ray ◽  
Constant Flow Rate ◽  
Significant Impairment ◽  
Working Principle ◽  
After Hours ◽  
Serial Femtosecond Crystallography

Serial femtosecond crystallography (SFX) using X-ray free-electron laser (FEL) sources has the potential to determine the structures of macromolecules beyond the limitation of radiation damage and without the need for crystals of sufficient size for conventional crystallography. In SFX, a liquid microjet is used to inject randomly oriented crystals suspended in their storage solution into the FEL beam. Settling of crystals in the reservoir prior to the injection has been found to complicate the data collection. This article details the development of an anti-settling sample delivery instrument based on a rotating syringe pump, capable of producing flow rates and liquid pressures necessary for the operation of the injector. The device has been used successfully with crystals of different proteins, with crystal sizes smaller than 20 µm. Even after hours of continuous operation, no significant impairment of the experiments due to sample settling was observed. This article describes the working principle of the instrument and sets it in context with regard to the experimental conditions used for SFX. Hit rates for longer measuring periods are compared with and without the instrument operating. Two versions of the instrument have been developed, which both deliver sample at a constant flow rate but which differ in their minimum liquid flow rates and maximum pressures.

Transparent Conductive Cu-In-O Thin Films Deposited by Reactive DC Magnetron Sputtering with Different Targets

2011 ◽  
Vol 239-242 ◽  
pp. 2752-2755
Author(s):  
Fan Ye ◽  
Xing Min Cai ◽  
Fu Ping Dai ◽  
Dong Ping Zhang ◽  
Ping Fan ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Optical Band Gap ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
Equal Distance ◽  
Transmittance Curve

Transparent conductive Cu-In-O thin films were deposited by reactive DC magnetron sputtering. Two types of targets were used. The first was In target covered with a fan-shaped Cu plate of the same radius and the second was Cu target on which six In grains of 1.5mm was placed with equal distance between each other. The samples were characterized with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV/VIS spectrophotometer, four-probe measurement etc. SEM shows that the surfaces of all the samples are very smooth. EDX shows that the samples contain Cu, In as well as O, and different targets result in different atomic ratios of Cu to In. A diffraction peak related to rhombohedra-centered In2O3(012) is observed in the XRD spectra of all the samples. For both the two targets, the transmittance decreases with the increase of O2flow rates. The direct optical band gap of all the samples is also estimated according to the transmittance curve. For both the two targets, different O2flow rates result in different sheet resistances and conductivities. The target of Cu on In shows more controllability in the composition and properties of Cu-In-O films.

In-situ X-ray tomographic imaging study of gas and structural evolution in a commercial Li-ion pouch cell

2022 ◽  
Vol 520 ◽  
pp. 230818
Author(s):  
Wenjia Du ◽  
Rhodri E. Owen ◽  
Anmol Jnawali ◽  
Tobias P. Neville ◽  
Francesco Iacoviello ◽  
...  
Keyword(s):  
Structural Evolution ◽  
Imaging Study ◽  
Tomographic Imaging ◽  
X Ray ◽  
Li Ion

The Effect of Hematocrit on the Clearance of Small Molecules during Hemodialysis

1983 ◽  
Vol 6 (3) ◽  
pp. 127-130 ◽  
Author(s):  
C. Woffindin ◽  
N.A. Hoenich ◽  
D.N.S. Kerr
Keyword(s):  
Blood Flow ◽  
Regression Analysis ◽  
Small Molecules ◽  
Flat Plate ◽  
Flow Rate ◽  
Distribution Curve ◽  
Blood Flow Rate ◽  
Hollow Fibre ◽  
Urea Clearance ◽  
Flow Rates

Data collected during the evaluation of a series of hemodialysers were analysed to see the effect of hematocrit on the clearance of urea and creatinine. All evaluations were performed on patients with a range of hematocrits with a mean close to 20%. The urea clearance of those in the upper half of the distribution curve (mean hematocrit 29.4%) was not significantly different from that of patients in the lower half of the distribution curve (mean hematocrit 16.9%) whether the clearance was studied at high or low blood flow rates and with hollow fibre or flat plate disposable hemodialysers. Likewise, there was no correlation between hematocrit and urea clearance by regression analysis. In contrast, the clearance of creatinine was affected by hematocrit being greater at lower hematocrit values. This difference was independent of blood flow rate and dialyser type and was confirmed by regression analysis.

Derecruitment of filtration surface area in paraquat-injured isolated dog lungs

1990 ◽  
Vol 68 (4) ◽  
pp. 1581-1589 ◽  
Author(s):  
T. Shibamoto ◽  
J. C. Parker ◽  
A. E. Taylor ◽  
M. I. Townsley
Keyword(s):  
Blood Flow ◽  
Surface Area ◽  
Vascular Resistance ◽  
High Flow ◽  
Base Line ◽  
Flow Rates ◽  
Blood Flows ◽  
Capillary Filtration Coefficient ◽  
Specific Index ◽  
Filtration Surface

The capillary filtration coefficient (Kf,c) is a sensitive and specific index of vascular permeability if surface area remains constant, but derecruitment might affect Kf,c in severely damaged lungs with high vascular resistance. We studied the effect of high and low blood flow rates on Kf,c in papaverine-pretreated blood-perfused isolated dog lungs perfused under zone 3 conditions with and without paraquat (PQ, 10(-2) M). Three Kf,cs were measured successively at hourly intervals for 5 h. These progressed sequentially from isogravimetric blood flow with low vascular pressure (I/L) to high flow with low vascular pressure (H/L) to high flow with high vascular pressure (H/H). The blood flows of H/L and H/H were greater than or equal to 1.5 times that of I/L. There were no significant changes in Kf,c in lungs without paraquat over a 50-fold range of blood flow rates. At 3 h after PQ, I/L-Kf,c was significantly increased and both isogravimetric capillary pressure and total protein reflection coefficient were decreased from base line. At 4 and 5 h, H/L-Kf,c was significantly greater than the corresponding I/L-Kf,c (1.01 +/- 0.22 vs. 0.69 +/- 0.09 and 1.26 +/- 0.19 vs. 0.79 +/- 0.10 ml.min-1.cmH2O-1.100 g-1, respectively) and isogravimetric blood flow decreased to 32.0 and 12.0% of base line, respectively. Pulmonary vascular resistance increased to 12 times base line at 5 h after PQ. We conclude that Kf,c is independent of blood flow in uninjured lungs. However, Kf,c measured at isogravimetric blood flow underestimated the degree of increase in Kf,c in severely damaged and edematous lungs because of a high vascular resistance and derecruitment of filtering surface area.

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